sible for putative dog PepT1 (dPepT1) activity reported earlier by us (FASEB J.

W38 Feeding of chicken or soy protein-based diet differentially affects

2001, 15: A829), we generated a full-length cDNA predicted to encode a 708 in vivo PepT1 uptake capacity in dogs. B. Zanghi*1, G. Sipe1, G. Davenport2,
amino acid-protein from MDCK cells using 5′- and 3′-RACE and RT-PCR and J. Matthews1, 1University of Kentucky, Lexington, 2The IAMS Company,
methodologies. Dog PepT1 shares 81, 83, and 83% amino acid identity with Lewisburg, OH.
human, sheep, and pig PepT1, respectively. To characterize the functional ac-
tivity of dPepT1, non-polarized Opossum Kidney (OK) cells were transiently Intestinal Peptide Transporter 1 (PepT1) expression can be upregulated by in-
transfected with pcDNA3.1-dPepT1 or pEGFP-N1-dPepT1 (GFP-PepT1) plas- creasing amounts of dietary casein and certain dipeptides. Previously, we dem-
mids and glycylsarcosine (GlySar, 1 mM) uptake measured 48 h after transfec- onstrated that orally bolused [3H]cefadroxil (CEF, 40 µCi, 40 nmol) was a good
tion. With both dPepT1 and GFP-dPepT1, H+-dependent [3H]GlySar uptake substrate to detect changes in PepT1 uptake capacity in adult, female, mongrel
dogs (JAS, 2004, 82(1): A375). The objective of these experiments were to
(pmol•mg-1 protein⋅30 min-1) by transfected OK cells was optimal at pH 5.5 evaluate the effect of feeding isonitrogenous diets that contained chicken (C) or
(3.1 times greater (P < .0001) vs pH 7.5) and saturable (Km = 0.57 ± 0.25 mM). soy (S) protein sources on PepT1 functional capacity and total tract digestibil-
IC50 studies demonstrated that dPepT1 possesses a range of substrate affinities ity. CEF was bolused 4 (Exp. 1) or 14 h (Exp. 2) after feeding and 3H appear-
(TrpLeu: 38 µM, carnosine: 1200 µM, cefadroxil: 600 µM). GlySar uptake was ance, metabolism, and disappearance in blood, urine, and feces was measured.
similar with dPepT1 and dPepT1-GFP. Western blot analysis demonstrated im- Exp 1 compared the effect of 18-d feeding of C, S, and S supplemented with
munoreactivity of anti-pig PepT1 antibody for dPepT1 (92 kDa) in OK cell carnosine or glycylsarcosine diets on these CEF parameters using a 4 x 4 Latin
homogenates. To develop a cell culture model to study membrane-specific sub- Square design (n = 4; BW = 21.3 ± 2.5 kg), whereas Exp 2 evaluated 39-d
strate- or hormone-dependent regulation of dPepT1, polarized OK cells were feeding of C versus S diets with a crossover design (n = 3). For Exp 1 and 2, the
transfected with dPepT1 and GlySar uptake (pmol⋅well-1⋅90 sec-1) measured. C diet had a greater (P < 0.05) apparent total tract DM, OM, CP (92 vs 86%),
Apical GlySar uptake was 8 times greater (P < .01) than basolateral. This report DE, and NDF digestibility versus any S diet. In Exp 1, plasma content (pmol) of
uniquely describes the molecular and functional characterization of dog PepT1, CEF from 3.5 or 5.5 h through 12 h after dosing (renal retention capacity) was
and demonstrates that a useful cell model to study membrane trafficking and 19 or 24% greater (P < 0.06) with the C diet than the S diet. In Exp 2, plasma
membrane-specific regulation of PepT1 has been established. content of CEF was 200 or 89% greater from 0 through 1.5 h or 2.5 h, respec-
tively, after dosing (intestinal uptake capacity) with the S diet than C diet. No
Key Words: Canine, Peptide Transport, GFP-PepT1 treatment effects were observed for CEF metabolism or 3H disappearance from
plasma or urine in either experiment. Within a dietary treatment and across
experiments, intestinal and renal CEF absorption capacity increases in the post-
prandial state of dogs fed a C diet, whereas CEF absorption capacity is about
the same in the postprandial and fasting state of dogs fed a S diet. These data
indicate that C and S diets differentially affect in vivo PepT1 functional capac-
ity.
Key Words: Canine, Intestine, Cefadroxil

Dairy Foods: Dairy Microbiology and Dairy Processing

W39 Quality characteristics and consumer acceptance of yogurt forti- W40 Effect of milk heat treatment on the growth and viability of
fied with date fiber. I. Hashim*, A. Khaul, and H. Afifi, UAE University, Al Bifidobacterium animalis Bb12 during fermentation and storage of yogurt.
Ain, United Arab Emirates. L. Fachin and W. Viotto*, State University of Campinas - UNICAMP, Faculty
of Food Engineering, Department of Food Technology, Campinas, SP, Brazil.
Milk and dairy products do not contain fiber while the by-product produced
during date syrup production is a good source of dietary fiber. The objective of Production of yogurt with Bifidobacterium spp. has being attracting much at-
this study was to investigate the effects of date fiber (DF) fortification on yo- tention in the last years due to health benefits of these microorganisms. How-
gurt quality and sensory properties. Quality characteristics, sensory properties ever, it is claimed that a minimum level of these bacteria (usually 106 cfu/g of
and consumer acceptance of yogurt fortified with DF were evaluated. Yogurt the product) should remain viable at the moment of consumption. Many studies
samples were prepared from whole milk using a commercial yogurt formula have pointed to the low viable counts of these microorganisms during shelflife.
(2.5% milk solid nonfat, 0.6% stabilizer and commercial yogurt culture). Con- Lactulose is a known prebiotic that is produced by severe heat treatments of the
trol yogurt and yogurts containing 1.5, 3, and 4.5% DF as well as 1.5% wheat milk. The objective of this work was to evaluate the effect of the heat treatment
bran (WF) were prepared. Acidity (1.04) and pH (4.47) of yogurt were influ- of 142°C/15 s comparing to the control one, 90°C for 5 minutes, on the growth
enced by DF fortification (1.08 and 4.61-4.65). Yogurts fortified with DF had of Bifidobacterium animalis BB 12 during yogurt fermentation and its viability
firmer texture (hardness 55-57) and darker color [lower L* (75.4-84.8) and during storage, monitoring textural changes, sineresis and yogurt post-acidifi-
higher a* (2.7-4.9)] than control (L = 95.5 and a* = -.8) or WF (L=89.3 and a* cation. Heat treatment of 142°C/15 s had no effect on the growth of
= 0.8) yogurts. Hedonic ratings by 32 consumers indicated that yogurt appear- Bifidobacterium animalis Bb12 during yogurt fermentation and on its viability
ance (8.3) and color (8.5) were significantly affected by the addition of DF during storage. Yogurt post-acifdification also did not change but heat treat-
(6.2-6.5). Yogurt containing up to 3% DF had similar hedonic ratings for sour- ment impaired texture, decreasing hardness, gummines and adhesiveness of the
ness, sweetness, firmness and overall acceptance as the control yogurt. Increas- product. Whey separation, however, was slightly improved compared to the
ing DF to 4.5% decreased sensory ratings and acceptability of yogurt signifi- control.
cantly.
Key Words: Heat Treatment, Probiotic, Yogurt
Fortifying yogurt with 3% DF produced acceptable yogurt with beneficial health
effects.
Acknowledgements: This study was funded by the Research Council at United W41 Effect of Propionibacterium freudenreichii PS-1 on the growth
Arab Emirates University. and viability of Bifidobacterium animalis Bb12 during fermentation and
storage of yogurt. L. Fachin and W. Viotto*, State University of Campinas -
Key Words: Yogurt, Date Fiber, Quality and Consumer Acceptance UNICAMP, Faculty of Food Engineering, Department of Food Technology,
Campinas, SP, Brazil.
Bifidobacterium spp. is increasingly being incorporated into dairy foods, espe-
cially yogurt, due to their health benefits. However, many studies have shown

266 J. Anim. Sci. Vol. 83, Suppl. 1/J. Dairy Sci. Vol. 88, Suppl. 1
low viability of these microorganisms during shelflife. Consequently, much at- Lactobacillus acidophilus or Lactobacillus casei was incorporated in the yo-
tention is being paid to increase growing and survival of these microorganisms gurt mix immediately after inoculation with Streptococcus thermophilus and
in dairy foods. In the last decade, some studies have pointed to the ability of Lactobacillus bulgaricus. Short, medium and long chain lengths inulins were
Propionibacterium spp. in producing some bifidus growth promoter metabo- incorporated at the rate of 1.5% w/w yogurt mix. Total solids in the control was
lites. The objective of this work was to study the effect of Propionibacterium kept constant with non fat dry milk. Viscosity, pH, syneresis, instrumental color
freudenreichii PS-1 on the growth of Bifidobacterium animalis Bb 12 during (L*,a*,b*), sensory flavor, body texture, appearance and color of the yogurts were
yogurt fermentation and its viability during storage, monitoring textural changes, studied at days 1, 11 and 22 after product manufacture. Readings were recorded
sineresis and yogurt post-acidification. P. freudenreichii PS-1 decreased fer- in triplicate per replication. Two replications were conducted. Data were ana-
mentation time of yogurt by 1.2 hours while slightly increased Bifidobacterium lyzed by ANOVA using the Proc GLM of SAS. Significant differences were
growing during fermentation. Viability of B. animalis Bb 12 decreased 0.3 log determined at α=0.05.
cycles in yogurt with P. freudenreichii PS-1 and 0.8 cycles in control yogurt
during 4 weeks of storage at 7°C. Yogurt texture was drastically changed by In the yogurts made with Lactobacillus casei inulins of different chain lengths
addition of propionibacteria with a great increase in gumminess and adhesive- did not impact product viscosity, appearance, and b* values. Yogurts with inu-
ness of the product. Yogurt with P. freudenreichii PS-1 also showed a lesser lins had significantly (p<0.05) higher L. casei counts compared to control.
tendency to post-acidification than the control one and it also decreased whey Freshly made (day 1) yogurts with either L. casei or L. acidophilus had signifi-
separation by half of its value after storage. cantly (p<0.05) higher flavor scores, lower body and texture scores, lower L*
Key Words: Bifidobacterium, Propionibacterium, Yogurt (lightness) values compared to yogurts stored for days 11 and 22.
In the yogurts made with Lactobacillus acidophilus inulins of different chain
lengths did not impact product viscosity, syneresis, pH, a* and b* values. Yo-
gurts with long and short chain length inulins had body and texture scores com-
W42 Development of symbiotic goat’s milk yogurt beverage. S. Li*, S. parable to the control. The interaction effect of chain length and storage time
Gokavi, and M. Guo, University of Vermont, Burlington. was significant (p<0.05) for L. acidophilus counts.
Goat’s milk and its products are gaining popularity in the USA and other devel- Chain length of inulins did not impact most of the characteristics of probiotic
oped countries and they are considered as specialty foods. The objectives of the yogurts.
study were to develop symbiotic beverages; and to evaluate the viability of
probiotics during storage. Four prototypes were developed: Plain (A), Vanilla Key Words: Symbiotic, Fermented, Milk
(pH 4.1) (B), Strawberry (pH 3.8) (C) and Vanilla (pH 3.8) (D). Yogurt base
was made using the starter culture Yofast-20 (mixture of S. thermophilus, L.
delbrueckii ssp. bulgaricus, L. acidophilus, Bifidobacterium ssp. and L. casei)
from Chr. Hansen. To the yogurt base sugar, inulin, pectin, water, strawberry W44 Fat free lemon and strawberry flavored yogurts fortified with
flavor, strawberry concentrate, beet extract, citric acid and probiotic supple- folic acid. C. Boeneke* and K. Aryana, Louisiana State University Agricul-
ment (ABC -1 containing L. acidophilus, Bifidobacterium, spp. and L. casei) tural Center, Baton Rouge.
were added as per the prototypes and then homogenised. The beverages were
Folic acid fortification is used in the prevention of neural tube defects such as
stored under refrigerated conditions and analysed for changes in pH, titratable
spina bifida and anencephaly, heart defects, facial clefts, urinary tract abnor-
acidity (TA) and viscosity. The probiotics were also enumerated every week to
malities, and limb deficiencies. Although yogurt is not a good source of folic
determine their viability during storage. Total solids of the beverages ranged
acid, fortification could aid in prevention of above mentioned defects. The ob-
from 17.2-17.8, protein 2.5-2.6, fat 2.9, ash 0.6-0.7 and carbohydrates 11.1-
jective of this study was to examine the effect of different concentrations and
11.9%. The beverages had calcium ranging from 148.0-165.3, phosphorous
stages of addition of folic acid on the physico-chemical and sensory character-
145.7-167.7, potassium 246.7-351.3 and sodium 64.0-78.9 mg/kg, respectively.
istics of flavored yogurts over a storage period. Fat free yogurts were manufac-
The values of pH, TA and viscosity were 4.10±0.03, 4.09±0.06, 3.83±0.06 and
tured using 0, 25%, 50%, 75% and 100% of the recommended daily allowance
3.83±0.06, 0.71±0.03, 0.71±0.02, 0.84±0.02 and 0.84±0.02%, 31.5±2.67,
of 400 micrograms of folic acid. Treatments included addition of folic acid at
31.1±4.43, 39.9±6.81 and 31.1±3.04 mPas for A, B, C and D, respectively. The
these levels before and after pasteurization and incorporation of lemon and straw-
initial population of L. acidophilus, Bifidobacterium spp. and L. casei were
berry flavoring. Data were analyzed using the General Linear Model procedure
3.17±2.2x10 7, 2.5±1.7x10 7, 3.7±1.8x10 7 and 1.8±1.1x10 7; 9.0±9.2x10 7,
with a completely randomized block design by the Statistical Analysis System.
8.58±2.2x108, 8.94±1.32x108 and 5.39±3.4x108; 2±1x106, 2±1x106, 4±3x106
Significant differences were determined at P<0.05 using Duncans Multiple
and 2±1x106 cfu/ml for A, B, C and D, respectively. Lactobacillus acidophilus
Range Difference Test. Lemon and strawberry pH values were lower than plain
was viable only for two weeks, however, Bifidobacterium spp. and L. casei
yogurt. Level of folic acid did not impact flavor scores. Mean flavor scores for
remained viable for 3 weeks and their viability will be studied for about 8-10
lemon and strawberry yogurts were higher than plain yogurts. Body and texture
weeks. The results indicate that goat’s milk may be a good vehicle for develop-
values of lemon and strawberry yogurts appeared to decrease over the five week
ing symbiotic beverages.
storage period. Addition of flavor to folic acid fortified yogurts helped improve
Acknowledgements: Authors would like to thank Oak Knoll dairy for provid- flavor scores.
ing goat’s milk for the studies.
Key Words: Folic Acid, Fortified
Key Words: Goat’s Milk, Symbiotic, Beverage

W45 Physical and sensory attributes of stirred yogurts: impact of the

W43 Fat free plain yogurt manufactured with inulins of various chain physical properties of initial gel and breakdown process. W. J. Lee* and J.
lengths and Lactobacillus acidophilus or Lactobacillus casei. K. Aryana*, A. Lucey, University of Wisconsin, Madison.
S. Begum, and P. McGrew, Louisiana State University Agricultural Center,
In stirred yogurts, the structure of the initial (intact) gel network and stirring
Baton Rouge.
method used for the disruption process, are crucial factors determining the sen-
Health benefits of inulin are several, namely; it is a dietary fiber, improves sory and textural properties. Objectives of this research were to study the rela-
activity of beneficial bacteria and increases calcium absorption. Dairy products tionships between physical and sensory properties of the initial yogurt gels and
such as fat free plain yogurt do not have fiber. Objective was to determine the stirred yogurts made from these gels. Yogurt gels were prepared from milk heated
impact of short, medium and long chain inulins on the physico-chemical, sen- at 75 or 85°C for 30 min and incubated at 32, 38, or 44°C. Stirred yogurts were
sory and microbiological characteristics of fat free plain yogurt manufactured made by shearing these gels at 5 s-1 for 1 min. Low amplitude oscillatory rheol-
with Lactobacillus acidophilus or Lactobacillus casei. ogy and shear rate sweeps were performed to determine the dynamic moduli
and apparent viscosity (AV), respectively. Quantitative descriptive analysis was

J. Anim. Sci. Vol. 83, Suppl. 1/J. Dairy Sci. Vol. 88, Suppl. 1 267
used to determine the sensory attributes of stirred yogurts. Increasing milk heating harvested by centrifugation and suspended in a sterile solution of sodium algi-
temperature and decreasing incubation temperature resulted in gels with higher nate which was allowed to drip slowly into a vessel containing CaCl2 solution
storage modulus, AV values at structural breakdown point, and yield stress and to obtain 2 mm beads with a concentration of 5 X 106 cfu/g. Free and immobi-
with lower maximum in loss tangent and permeability values. In the very low lized L. casei cells were incubated in 0.01 N HCl at 150 rpm and 37°C for 1 h
shear rate region (i.e. 0.01 to 0.1 s-1), the AV initially increased with increasing to simulate the transit through the stomach. Survivals of 2 and 40% were mea-
shear rate due to the resistance posed by the intact network; this behavior could sured for the free and immobilized cells respectively. The size of the beads
not be modeled with commonly used models for stirred yogurt. In stirred yo- decreased in 30% after the incubation. The sensory evaluation results indicated
gurts, the use of higher heating and lower incubation temperatures resulted in a good acceptance of the dessert with the incorporated immobilized L. casei
increased AV, oral viscosity, and the sensory mouth coating attribute as well as cells. It can be concluded that a good functional dairy product could be ob-
a decreased particle size. A positive relation was observed between storage tained by this method and that immobilization actually improved the survival
modulus of initial gels and oral viscosity (r = 0.77) while permeability was of the microorganisms.
negatively correlated with oral viscosity (r = -0.84) and AV at low (10 s-1) shear
rate (r = -0.73) of stirred yogurt. Maximum in loss tangent during the initial Acknowledgements: The authors appreciate the financial aid of COFAA and
gelation phase was negatively correlated with oral viscosity (r = -0.85), mouth CGPI-IPN.
coating attribute (r = -0.88), and AV at low (10 s-1) shear rate (r = -0.78). In Key Words: Probiotics, Immobilization, Arroz con Leche
conclusion, the physical properties of initial yogurt gels had a significant influ-
ence on the physical and sensory properties of stirred yogurts.
Key Words: Yogurt, Rheology
W48 Assessment of potential probiotic properties of Latobacilli strains
isolated from traditionally home-made Koumiss in Inner Mongolia of
China. H. Zhang*1, T. Sun1, J. Xu1, L. Wang1, Y. Yun1, B. Menghe1, R. Wu1, J.
W46 Sensory description of plain yogurt made from milk of different Wang1, and M. R. Guo2, 1Inner Mongolia Agricultural University, Huhhot, In-
origins. M. Almena*, K. McEvoy, B. Yon, and A. Howard, University of Ver- ner Mongolia, China, 2University of Vermont, Burlington.
mont, Burlington. Fifty strains of Lactobacilli isolated from 16 samples of traditionally home made
The goal of this study was to evaluate the sensory characteristics and consumer koumiss in Inner Mongolia of China were assessed for their potential probiotic
acceptability of different varieties of plain yogurt made from cow, sheep, goat, properties. L.Casei ZL3-6 and L.acidophilus ZL12-1 were screened out for their
water buffalo (WB) and soy milk, respectively. A trained sensory panel evalu- resistance and tolerance to the in vitro gastrointestinal digestion. L. CaseiZL3-
ated the samples in terms of appearance, texture and flavor characteristics us- 6 showed higher ability of resistance to bile salt compared with L. acidophilus
ing descriptive analysis. Commercial samples from each yogurt were evaluated ZL12-1. They can still grow in the media containing 1.6% and 0.3% of bile salt
by a convenience sample of 109 consumers enlisted at a supermarket that spe- for L.casei ZL3-6 and L. acidophilus ZL12-1, respectively. Both of L. casei
cializes in natural and gourmet foods. Consumers were asked to select the most ZL3-6 and L. acidophilus ZL12-1 can hydrolyze bile salt to liberate free bile
and least favorite sample, and to rate the texture and flavor of the 5 samples acid in the growth media. There is no significant difference in activity between
using a 9-pt hedonic scale. The questionnaire also included demographic and the two strains during the period of incubation at 37C for 24 h. The two strains
eating habits information. Data were statistically analyzed by ANOVA and Chi- showed a strong ability of removing cholesterol from the growth media 49.61%
square tests using SPSS. Cow milk yogurt was characterized as having a smooth by L. casei ZL3-6 and 32.39% by L. acidophilus ZL12-1, respectively. The
appearance, creamy texture with high acetaldehyde notes and low acidity. The results indicate that the two isolated strains may be the potential candidates for
WB yogurt had a distinctive white-porcelain color, very thick and firm texture, developing probiotics.
with low sweetness and acidic flavor, in contrast to the soy yogurt which had Key Words: Koumiss, Probiotic, Lactobacilli
brown color, chalky texture and high sweetness. Sheep milk yogurt had granu-
lar appearance, curdy texture and strong sour flavor. Goat milk yogurt also had
strong flavor but smooth and creamy texture. Strong significant differences (P≤
.001) were identified between the texture scores among consumer data. Goat
W49 High protein buttermilk powder; manufacture and properties.
yogurt had the highest texture score and WB yogurt had the lowest. No signifi-
V. V. Mistry* and J. R. Dornellas, South Dakota State University, Brookings.
cant differences between genders were found in terms of flavor or preferences.
However, consumer eating habits, especially the type of yogurt regularly con- A process was developed to manufacture a sweet buttermilk ingredient powder.
sumed (plain or flavored), strongly determined the acceptability of the product. The process involved the concentration of sweet buttermilk by ultrafiltration to
Individuals who regularly consumed plain yogurt significantly preferred the approximately 5X concentration, followed by double diafiltration to 5X with
WB and goat milk yogurts (P ≤.01), and identified the soy yogurt as least favor- water. The initial protein content of buttermilk was 2.9% and the final 15.9%
ite. However, consumers who eat flavored yogurt preferred the soy milk prod- (21% total solids). Powders were manufactured from buttermilk that was
uct, probably due to the higher sweetness level (soy yogurt included sugar, though ultrafiltered as well as from diafiltered buttermilk. The concentrates were spray-
labeled as “plain”). dried in a single-stage, gas-fired spray dryer with a rotary atomizer at an inlet
air temperature of 200°C and outlet air temperature of 85 to 95°C. The powders
Key Words: Yogurt Sensory Evaluation, Milk Type
from ultrafiltered buttermilk had a protein content of approximately 61.5%,
4.9% moisture and 13.3% lactose. The diafiltered powder had a protein content
of approximately 73% and a moisture content of 5.3% and 1% lactose. Powders
were packaged and stored under four storage conditions; room temperature and
W47 Incorporation and survival of immobilized probiotic bacteria in refrigerated storage under vacuum packaging, and room and refrigerated tem-
arroz con leche, a Mexican dairy dessert. H. Hernandez-Sanchez*, E. Alvarez, perature storage under atmospheric conditions. Powders were tested for solu-
and M. Labastida, Instituto Politecnico Nacional, Mexico, DF, Mexico. bility index, oxidation, and gelation. Storage studies over six months revealed
Lactobacillus casei has been shown to be a probiotic bacteria with therapeutic no off-flavor development during storage under refrigerated or room tempera-
and immunomodulatory properties and able to colonize the intestine when in- tures or under vacuum or atmospheric conditions. Powders produced with
gested in dairy products. Immobilization has been used in probiotic cultures to diafiltration and having over 72% protein had a typical protein flavor. Solubil-
increase their survival during their transit through the gastrointestinal system. ity index of ultrafiltered powders (4.6 mL) was significantly lower than those of
If the size of the beads of immobilized microorganisms is big, the consumers diafiltered powders (22.7 mL). Heat induced gels were prepared from the pow-
may not like it. Foods with particles in suspension could be good options to ders by reconstituting powder to 15% protein in water using and adjusting pH
incorporate the immobilized probiotics and this is the case of Arroz con Leche, to 6.0. The liquids were then heated to 80°C for one hour and cooled under
a popular dairy dessert in Latin America which includes rice, milk, sugar and running tap water for 2 hours. Gels were stored at 7°C overnight before measur-
cinnamon in its preparation. L. casei was grown in MRS broth and the cells ing firmness using a penetrometer. Firmness of the ultrafiltered powders was
276.4 mm and that of the diafiltered powders was 345 mm. This process offers

268 J. Anim. Sci. Vol. 83, Suppl. 1/J. Dairy Sci. Vol. 88, Suppl. 1
opportunities for the production of high protein powders from sweet buttermilk and interactions between variables. A panel of nine judges rated samples on a
for food applications. triplicate basis. Training took nine one-hour sessions and was followed by regular
evaluation sessions. The samples were rated on a 15-cm line scale and data
Key Words: Buttermilk, Protein, Drying obtained was analyzed using SAS® statistical software. Significant differences
between the three types of butters were obtained on yellow, acidic odor (p<0.001),
cheese odor, cardboard odor, acidic and grassy flavors (p<0.01), porous, hard,
W50 Effects of packaging material, storage temperature, and fat con- shiny, mouth coating and nutty flavor (p<0.05). Cultured butter was signifi-
tent on the changes of the chemical composition of Ultrapasteurized milk cantly shinier than whey butter and had a higher score than regular butter. Whey
bottled in amber polyethylene Terephthalate (PET) containers. J. Bailard*, butter was more yellow than cultured butter, which in turn was more yellow
W. Harper, M. Pascall, and V. Alvarez, The Ohio State University, Columbus. than the regular butter. The whey butter was more porous, and had higher scores
on nutty flavor and cardboard odor than regular and cultured butters. Regular
Shelf life of high temperature short time (HTST) milk is 14-21 days. Ultra- butter was significantly harder than cultured butter but not whey butter. Cul-
pasteurization (UP) milk is heated to temperatures higher than HTST, increas- tured butter had more mouth coating, acidic odor and flavor and grassy flavor
ing shelf life. Packaging and heat affect shelf life. Polyethylene terephthalate than regular and whey butters. The commercial samples were more porous,
(PET) bottles are better barriers to moisture and oxygen compared to polyethyl- crumbly, and had more artificial butter odor, rancid odor and flavor and card-
ene. Amber colored PET reduces light oxidization, decreasing flavor changes board odor. Results from Principal Component Analysis indicated that DPTC
and spoilage. Extending the shelf life of milk increases its competitiveness in Whey butter and DPTC Regular butter were similar and were characterized by
the beverage industry. The objective is to determine the effect of storage tem- a sweet taste. Whey butter characteristics compared very favorable with com-
perature and fat levels on shelf life of UP milk in amber PET bottles. Skim and mercial cultured butter and was very similar to regular butter.
whole milk were ultrapasteurized and aseptically packaged in amber PET bottles
and stored at 24°C and 7°C. Milk stored at 24°C was sampled every 3 days for Key Words: Butter, Sensory Analysis, Cultured Butter
30 days, and milk stored at 7°C was sampled every 6 days for 90 days. Dis-
solved oxygen, headspace oxygen, and standard plate count were analyzed. Milk
samples were analyzed with an electronic nose based on negative chemical ion- W53 Characterization of slow acid-producing Streptococcus
ization with gas chromatography used to verify results. Milk stored at 24°C has thermophilus strains. R. J. McCarthy*, O. Anggraeni, W. J. Harper, and P. D.
a shorter shelf life than refrigerated milk. The headspace of skim and whole Courtney, The Ohio State University, Columbus.
milk stored under refrigeration and at 24°C decreased over a 90 day and 30 day
period, respectively. The dissolved oxygen for the 24°C decreased over time for The simultaneous manufacture of quality Swiss cheese and kosher-certified whey
whole and skim milk compared to the refrigerated milk which increased over is a challenge. Over-acidification of the curd at the lower cook temperatures
time. SPC showed no growth for 90 day refrigerated milk and for 24°C stored required for kosher whey can result in low-grade cheese. Slow acid-producing
milk. Using electronic nose, volatiles in skim milk and whole milk were able to Streptococcus thermophilus strains may slow curd acidification at the kosher
be separated. Electronic nose data was consistent with shelf life results with cook temperature. The objective was to compare growth, acid production, and
volatiles being comparable at different time points, indicating the milk was gene expression of S. thermophilus for potential use in a kosher process. Thir-
acceptable until 90 days. teen slow acid producing S. thermophilus cultures were obtained from culture
manufacturers. One fast acid producing culture was included for comparison.
Key Words: Polyethylene Terephtalate (PET), Ultra-Pasteurization, Shelf Life Each strain was inoculated into UHT milk, pre-warmed to 48.3°C or 51.7°C.
UHT milk and a standard inoculation rate standardized conditions for all strains.
Colony forming units and pH were monitored over time. Strains were geneti-
W51 Effects of evening primrose oil addition on quality of cholesterol- cally typed by pulsed field gel electrophoresis of genomic DNA treated with
removed butter and lowering blood cholesterol. T. H. Jung, J. J. Kim, S. H. SmaI or ApaI. Genetic profiles were compared using statistical software. The
Yu, and H. S. Kwak*, Sejong University, Seoul, Korea. ATPase and urease genes were amplified from one S. thermophilus strain by
PCR and used as probes in Southern hybridizations. Northern blots determined
This study was designed to carry out effects of evening primrose oil (EPO, intensity of gene expression in log and stationary phases. Ten of the 13 strains
containing 80% gamma-linolenic acid) on quality of cholesterol-removed but- reduced the pH slower than the control, fast acid producing strain. Growth rates
ter during 8 week storage and lowering blood cholesterol in rats. Three different or final cell densities correlated with acid production. The final pHs ranged
treatments were control (no β-CD, no EPO), β-CD-treated butter (10% β-CD, from 4.93 to 5.59. Strains S754 and S847 reduced the pH to only 5.59 and 5.4,
no EPO) and EPO-added and β-CD-treated butter (10% β-CD, 2% EPO). The respectively, suggesting acid sensitivity in these strains. No clustering of slow
rate of cholesterol removal reached 92.7%. TBA value was higher in EPO-added acid production or acid sensitivity was observed in the comparison of DNA
and cholesterol-removed group than others throughout storage periods. Most of restriction profiles. Six strains were selected for further genetic analysis. South-
rheological values in EPO-added and cholesterol-removed butter increased with ern blots confirmed the presence of ATPase and urease genes. Northern blots
storage period, and were similar to those in control. Especially, scores of hard- indicated a difference in gene expression among the six strains and a correla-
ness and cohesiveness were higher in β-CD-treated butter. In sensory analysis, tion between expression level and acid production. Results may assist in selec-
most of properties except texture and color were affected adversely in EPO tion of S. thermophilus strains for slow acid production at low cook tempera-
addition at every storage period. In animal study, total blood cholesterol was tures, potentially allowing quality cheese and kosher whey production.
significantly lower in β-CD-treated group, and EPO-added and β-CD-treated
group as 201.8 and 190.5 mg/dL, respectively, compared with that in control as Key Words: Streptococcus, Swiss Cheese, Kosher Whey
230.0mg/dL after 6 week feeding. The present results indicated that although
EPO addition resulted in high TBA value and impaired sensory quality, total
blood cholesterol and triglyceride were lowered in rats. W54 Application of exopolysaccharide-producing cultures in making
Key Words: Evening Primrose Oil, Blood Cholesterol, β-Cyclodextrin reduced fat Cheddar cheese. Composition and proteolysis. S. Awad*, A.
Hassan, and F. Halaweish, South Dakota State University, Brookings.
In a previous study, EPS-producing cultures produced reduced fat Cheddar cheese
W52 Sensory evaluation of regular, whey and cultured butters. S. with physical properties similar to those of its full fat counterpart. This reduced
Jinjarak*, A. Olabi, R. Gonzalez, W. Lires, and R. Jimenez-Flores, California fat cheese developed bitterness after 3 months of ripening. The objective of this
Polytechnic State University, San Luis Obispo. work was to monitor proteolysis during ripening of reduced fat Cheddar cheeses
made with different EPS-producing and nonproducing cultures. Results showed
The objective of this work was to characterize the sensory qualities of whey, that the actual yield, moisture, moisture in the nonfat substance (MNFS) and
cultured and regular unsalted butters produced at the Dairy Product Technology residual coagulant activity were significantly higher in cheese made with a ropy
Center (DPTC; n=3) or obtained from commercial sources (n=6). Descriptive strain of Lactococcus lactis ssp. cremoris (JFR1) than in all other reduced fat
analysis was performed to determine the significant differences between samples cheeses. Proteolysis, as determined by polyacrylamide gel electrophoresis and

J. Anim. Sci. Vol. 83, Suppl. 1/J. Dairy Sci. Vol. 88, Suppl. 1 269
the level of water soluble nitrogen, was also higher in cheese made with JFR1 but delayed ATCC9614 growth. L856 slurry serum also slightly delayed
than in all other reduced fat cheeses. However, cheese made with JFR1 con- ATCC9614 growth compared with the control serum. Slurry sera from different
tained the least amount of free amino acids among all cheeses. RP-HPLC analysis L. helveticus strains differed in their peptide profiles, which may contribute to
showed a significant increase of hydrophobic peptides (causing bitterness) dur- the observed differences in P. freudenreichii growth. The slurry serum model
ing storage of cheese made with JFR1. The results showed that bitterness in has potential for screening P. freudenreichii and L. helveticus pairings for Swiss
reduced fat Cheddar made with EPS-producing cultures resulted from the high cheese manufacturing.
moisture level and chymosin activity. This study recommends using debittering
cultures in conjugation with EPS-producing strains in making reduced fat Ched- Key Words: Propionibacterium freudenreichii, Lactobacillus helveticus, Swiss
dar. Cheese

Key Words: Reduced Fat Cheddar Cheese, Exopolysaccharides, Bitterness

W56 Processing factors that affect the quality of pilot plant scale Swiss
type cheese. C. J. Kuo*, N. Koca, T. Ji, V. B. Alvarez, and W. J. Harper, The
W55 Propionibacterium freudenreichii growth is differentially affected Ohio State University, Columbus.
by the serum of Swiss cheese slurries prepared with different Lactobacillus
helveticus strains. P. Limpisathian*, W. J. Harper, and P. D. Courtney, The Industry reports frequent problems with overset eyes when using the Kosher
Ohio State University, Columbus. requirement of cooking to less than 49 deg. C. Work with Swiss cheese made
under pilot plant conditions showed that overset eyes occurred in most cheese
Swiss cheese makers report that some combinations of L. helveticus and P. being cooked at 48 deg. C and not in cheese cooked at 53 deg. C, a standard
freudenreichii cultures result in poor eye and flavor formation, whereas other make procedure. Twenty-six blocks of Swiss type cheese were made at the uni-
combinations perform well. The objective was to develop a rapid method to versity pilot plant over 6 processing days as an attempt to find the most impor-
predict successful strain pairings. Cheese curds were prepared aseptically from tant processing factors that affect the cheese quality. Combination of different
UHT milk using S. thermophilus alone (control) or S. thermophilus plus one of ratios of starter organisms, method of placing curds into molds, and method of
four L. helveticus strains. Curds were homogenized into a slurry with 60% pressing were selected as the variables for the trials. After 21 days in the warm
moisture and 1% salt in moisture. The slurries were centrifuged, and the result- room (22°C), the products were compared based mainly on the quality of eye
ing serum was filtered. Each sterile slurry serum was added to chemically de- formation. Changes in starter culture ratio and in curd placing method did not
fined medium (CDM) lacking amino acids. One of five P. freudenreichii strains improve the eye quality significantly. At the same curd pH at dipping (6.4),
was inoculated into CDM containing each slurry serum, and growth was moni- increase weight to more than two folds during pressing made marked improve-
tored spectrophotometrically. Maximum growth rate and lag phase were calcu- ment on eye quality. Higher pressure (not vacuum) also resulted in higher acetic
lated using the Richards model. Peptide profiles of slurry sera were observed and propionic acid contents. The data suggested that overset is primarily re-
using HPLC. Propionibacterium freudenreichii growth was not observed in lated to the greater number of nucleation sites due to a difference in curd tex-
CDM lacking slurry serum. CDM supplemented with slurry sera, including the tural properties. Preliminary treatment with vacuum in between first and sec-
control serum prepared without L. helveticus, supported the growth of four of ond pressing appeared to reduce overset and make for a denser structure. Opti-
the five P. freudenreichii strains to different extents. Propionibacterium mization of the vacuum treatment in respect to time and degree of vacuum
freudenreichii P764M1 did not grow with any slurry serum. Lactobacillus requires additional work. The vacuum treatment is not practical commercially,
helveticus L350 slurry serum stimulated growth of four P. freudenreichii strains but can provide an understanding of the mechanism of overset eyes common in
beyond that observed with the control serum. In contrast, L. helveticus L346 Kosher cook Swiss cheese.
slurry serum inhibited growth of these four strains in comparison to the control
serum. L887 slurry serum slightly stimulated P. freudenreichii P873 growth, Key Words: Swiss Type Cheese, Pilot Plant, Processing

Food Safety: Control of Hazards

W57 Effects of in-feed anti-salmonella egg yolk antibodies on shed- resistance was higher (P<.05) in E. coli from pigs fed antibiotics. In Experi-
ding and antibiotic resistance of bacteria in swine. S. Rattanatabtimtong*, ment two, although a treatment effect was observed immediately after transport
A. Mathew, S. Chattin, E. Jarboe, and R. Clift, University of Tennessee, Knox- (P<.001), neither ASEYA nor ceftiofur were effective in reducing salmonella
ville. shedding. These studies indicate that in-feed addition of anti-salmonella egg
yolk antibodies may not be effective in controlling shedding of salmonella in
Two experiments were conducted to determine effects of anti-salmonella egg swine.
yolk antibodies (ASEYA) on shedding of Salmonella enterica Typhimurium
and antibiotic resistance of E. coli. In Experiment 1, 132 weaned pigs in 2 Key Words: Salmonella, Egg Yolk Antibodies, Swine
replicate trials were randomly assigned to 6 dietary treatments including a con-
trol without additives or similar diets containing apramycin followed by
carbadox, or oxytetracycline, or ASEYA, or dried egg yolk lacking ASEYA, or
spray dried plasma protein. Following initiation of treatments, pigs were chal-
lenged with a S. Typhimurium. Fecal samples were collected prior to treatments, W58 Effect of grain processing on performance and fecal shedding of
just prior to challenge, and on various days until pigs reached market weight, E. coli O157 in finishing feedlot heifers. B. E. Depenbusch*, E. R. Loe, M.
for isolation of salmonella and E. coli to determine shedding and antibiotic C. Corrigan, T. G. Nagaraja, and J. S. Drouillard, Kansas State University, Man-
resistance patterns. In Experiment 2, 64 market-age pigs in 2 replicate trials hattan.
were randomly assigned to 4 treatments, including a control diet without addi-
Ninety-two crossbred yearling heifers (initial BW = 347 kg) were fed diets con-
tives, or diets containing ASEYA, or dried egg yolk without ASEYA, or IM
taining dry-rolled corn (DRC) or steam flaked corn (SFC) to assess the impact
injections of ceftiofur. Treatments were continued for 2 days, after which pigs
of grain processing on prevalence of E. coli O157. Steam flaking typically re-
were challenged with S. Typhimurium then mixed and transported to a holding
sults in more extensive ruminal digestion, and thus less substrate flow to the
facility to simulate shipping to market. Fecal samples were obtained prior to
hindgut, potentially altering populations of flora in the hindgut. During the
initiation of treatments, just prior to challenge and transport, immediately fol-
prescreening phase, heifers (n=92) were fed a common DRC finishing diet.
lowing transport, and at 24 and 48 hours following transport, for recovery of
Heifers were screened for presence of E. coli O157 using a fecal grab sample
salmonella. In Experiment 1, the percentage of pigs shedding salmonella was
(FECAL) and by swabbing the rectoanal mucosa (RAMS). Animals that tested
decreased (P<.05) for antibiotic treatments compared to other diets; however,

270 J. Anim. Sci. Vol. 83, Suppl. 1/J. Dairy Sci. Vol. 88, Suppl. 1