• Food Science of Animal Resources
• /
• v.31 no.6
• /
• pp.928-934
• /
• 2011

The objective of this study was to characterize the lactate metabolism and lipolysis in Emmental cheese made of Korean raw milk throughout the ripening periods; 14 d at $10^{\circ}C$, 42 d at $23^{\circ}C$, and 30 d at $4^{\circ}C$. Emmental cheese was made using a commercial starter culture with propionic acid bacteria (PAB) and without PAB as a control on the pilot plant scale. Changes in the contents of five organic acids (citric, lactic, formic, acetic, and propionic acid) and individual free fatty acids (FFAs) were measured using HPLC/PDA and GC/FID. As a result of propionic fermentation by PAB, the concentration of acetic acid and propionic acid increased up to 1.5 and 6.1 g/kg, respectively and the most dramatic increased occurred when incubated in the hot room ($23^{\circ}C$). Lactic, citric, and formic acid contents were 2.6, 2.5 and 0.8 g/kg at the end of ripening, respectively. As a result of lipolysis, the amount of total FFAs was 6,628.2 mg/kg. Compared to the control, levels of individual FFAs from butyric (C6:0) to linoleic (C18:2) acids increased significantly (p<0.05) during the ripening period. Especially, 65.1% of total FFAs was released in the $23^{\circ}C$ room and the most abundant FFAs were palmitic (C16:0), stearic (C18:0) and oleic acid (C18:1). These results demonstrated that the lipolysis of Emmental cheese was strongly affected by bacterial lipase from PAB.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.55 no.2
• /
• pp.102-110
• /
• 2022

This study was conducted to optimize the processing process for the oyster Crassostrea gigas gratin with cream sauce (OG-CS). The optimum concentration of added milk for oyster extract with milk (OE-M) was 35.0% based on the frozen-boiled oyster (F-BO), as suggested by the results of sensory evaluation. Response surface methodology was performed with whipping cream (WC)/[OE-M+mixed powder (garlic powder:onion powder=1:1) (MP)] (X₁) and OE-M/MP (X₂) as independent variables and viscosity (Y₁), amino acid nitrogen (Y₂), and overall acceptance for sensory evaluation (Y₃) as dependent variables. The optimal proportions were 74.55% of WC, 20.25% of OE-M, and 5.2% of MP, and the predicted multiple response optimal values for the dependent variables were 3,735.6 cP of Y₁, 197.0 mg/100 g of Y₂, and 6.2 score of Y₃. Under optimal conditions, the experimental values for Y₁, Y₂, and Y₃ were 3,711.9±30.0 cP, 198.1±1.9 mg/100 g, and 6.3±0.5 score, respectively, which were not significantly different from the predicted values (P>0.05). Further, the results of sensory evaluation suggested that the optimum concentration of macaroni:cheese (1:2) to be 46.2% based on the F-BO. The OG-CS prepared under these optimal conditions was superior to the commercial seafood gratin in overall acceptance.

• Animal Bioscience
• /
• v.37 no.8
• /
• pp.1398-1407
• /
• 2024

Objective: The objective of this study was to determine internal structure spectral profile of by-products from coffee processing that were affected by added-microorganism fermentation duration in relation to truly absorbed feed nutrient supply in ruminant system. Methods: The by-products from coffee processing were fermented using commercial fermentation product, consisting of various microorganisms: for 0 (control), 7, 14, 21, and 28 days. In this study, carbohydrate-related spectral profiles of coffee by-products were correlated with their chemical and nutritional properties (chemical composition, total digestible nutrient, bioenergy values, carbohydrate sub-fractions and predicted degradation and digestion parameters as well as milk value of feed). The vibrational spectra of coffee by-products samples after fermentation for 0 (control), 7, 14, 21, and 28 days were determined using a JASCO FT/IR-4200 spectroscopy coupled with accessory of attenuated total reflectance (ATR). The molecular spectral analyses with univariate approach were conducted with the OMNIC 7.3 software. Results: Molecular spectral analysis parameters in fermented and non-fermented by-products from coffee processing included structural carbohydrate, cellulosic compounds, non-structural carbohydrates, lignin compound, CH-bending, structural carbohydrate peak1, structural carbohydrate peak2, structural carbohydrate peak3, hemicellulosic compound, non-structural carbohydrate peak1, non-structural carbohydrate peak2, non-structural carbohydrate peak3. The study results show that added-microorganism fermentation induced chemical and nutritional changes of coffee by-products including carbohydrate chemical composition profiles, bioenergy value, feed milk value, carbohydrate subfractions, estimated degradable and undegradable fractions in the rumen, and intestinal digested nutrient supply in ruminant system. Conclusion: In conclusion, carbohydrate nutrition value changes by added-microorganism fermentation duration were in an agreement with the change of their spectral profile in the coffee by-products. The studies show that the vibrational ATR-FT/IR spectroscopic technique could be applied as a rapid analytical tool to evaluate fermented by-products and connect with truly digestible carbohydrate supply in ruminant system.

• Animal Bioscience
• /
• v.37 no.2
• /
• pp.173-183
• /
• 2024

Objective: This study aimed to evaluate whether the methane (CH₄) to carbon dioxide (CO₂) ratio (CH₄/CO₂) and methane-related traits obtained by the sniffer method can be used as indicators for genetic selection of Holstein cows with lower CH₄ emissions. Methods: The sniffer method was used to simultaneously measure the concentrations of CH₄ and CO₂ during milking in each milking box of the automatic milking system to obtain CH₄/CO₂. Methane-related traits, which included CH₄ emissions, CH₄ per energy-corrected milk, methane conversion factor (MCF), and residual CH₄, were calculated. First, we investigated the impact of the model with and without body weight (BW) on the lactation stage and parity for predicting methane-related traits using a first on-farm dataset (Farm 1; 400 records for 74 Holstein cows). Second, we estimated the genetic parameters for CH₄/CO₂ and methane-related traits using a second on-farm dataset (Farm 2; 520 records for 182 Holstein cows). Third, we compared the repeatability and environmental effects on these traits in both farm datasets. Results: The data from Farm 1 revealed that MCF can be reliably evaluated during the lactation stage and parity, even when BW is excluded from the model. Farm 2 data revealed low heritability and moderate repeatability for CH₄/CO₂ (0.12 and 0.46, respectively) and MCF (0.13 and 0.38, respectively). In addition, the estimated genetic correlation of milk yield with CH₄/CO₂ was low (0.07) and that with MCF was moderate (-0.53). The on-farm data indicated that CH₄/CO₂ and MCF could be evaluated consistently during the lactation stage and parity with moderate repeatability on both farms. Conclusion: This study demonstrated the on-farm applicability of the sniffer method for selecting cows with low CH₄ emissions.

• Journal of Microbiology and Biotechnology
• /
• v.10 no.2
• /
• pp.147-153
• /
• 2000

This study was conducted to compare probiotic activities and physiological functions of Bifidobacterium longum Mk-G7 with weveral commercial and type strains of bifidobacteria. bif. longum MK-G7 showed the highest acid tolerance against HCl and acetic acid, whereas bif. infantis Y-1 showed the lowest acid tolerance and more than 4 log cycles of viable cell count decreased due to acid injuty. Viable cell counts of bifidobacteria strains decreased more than 1.5 log cycles owing to oxygen toxicity, with the exception of Bif. longum MK-G7, Bif. infantis Y-2, Bif. longum Y-3, Bif. longum Y-6, and Bif. longum RD-13 showed the highest bile tolerance, whereas Bif. longum MK-G7 showed a medium level of bile tolerance. Only Bif. longum MK-G7 howed much higher antibiotic resistance against both tetracycline and penicillin-G in the MIC(minimum inhibitory concentration) level of 24.8 mg/I and 0.52mg/I, respectively. Bif longum Y-6, and Bif. bifidum ATCC 29539 showed more than 80% of anti-mutagenicity against NQO(4-nitroquinolinel-oxide). Since the production of cytokines such as $TNF(tumor necrosis factor)-{\alpha}$ and IL (interleukin)-6, and NO(nitric oxide) in the macrophage cell line Raw 264.7 cells increased as Bif. longum MK-G7 cell concentration increased, ti was suggested that Bif. longum MK-G7 is able to enhance immunopotentiating activity in vitro. When freeze-dred Bif. longum MK-G7 was administered to mice at the dose of 1,2,4, and 6 g/kg of body weight, all of the mice survived in all feeding groups, proving the GRAS(generally recognized as safe) status of Bif. longum MK-G7. When fermented milk containing Bif. longum MK-G7 was administered to human volunteers, viable cell count of total bifidobacteria and anaerobes in the feces increased up to 0.5 log cycles more than before the administration. In particular, Bif. logum MK-G7 ingibited the growth of Bacteroides at the level of 1.0-1.5 log cycles.

• Food Science of Animal Resources
• /
• v.23 no.2
• /
• pp.137-144
• /
• 2003

This study was carried out to investigate safety evaluation of IGEs separated and refined from bovine milk and commercial recombinant human IGFs. In order to evaluate toxicity of these samples, acute toxicity test and short term toxicity test were investigated with IGF-I separated and refined from colostrum and commercial recombinant human IGF-I from R&D systems company. for acute toxicity test, we selected recombinant human IGF-I from R&D systems company and establish one control group and three dose-level groups(0, 10, 20 and 50 $\mu\textrm{g}$ per rat). We have intravenously injected tail of rats with selected sample once. After 20 days, pathological cellular tissue analyses were investigated with liver, kidney and spleen of 12 rats in all test groups. However, Morbid tissue and abnormal statistical results were not discovered in all cellular tissues. For short term toxicity test, we selected IGF-I separated and refined from colostrum and establish one control group and three dose-level groups(0, 5, 10 and 15 $\mu\textrm{g}$/day per rat). Rats were orally injected with selected sample once a day during two weeks. After short term toxicity test period, Pathological cellular tissue analyses were investigate with liver, kidney and spleen of 12 rats in all test groups. However, Morbid tissue and abnormal statistical results were not discovered in all cellular tissues. These results suggest that IGF-I treated groups show no significant toxicological findings with changes of body weight, food consumption, water consumption, and pathological findings compared with control groups.

• Journal of Dairy Science and Biotechnology
• /
• v.34 no.4
• /
• pp.231-237
• /
• 2016

Kefir is a probiotic food. Probiotics have shown to be beneficial to health, and are currently of great interest to the food industry. Hence, this study was carried out to evaluate the lactase activity of kefir-isolated lactic acid bacteria. Three strains, Lactobacillu kefiri DH5 isolated from the kefir grains and Bifidobacterium animalis subsp. Lactis and Bifidobacteria longum 720, commercial probiotic LAB, were fermented in 10% reconstituted nonfat dry milk suspensions and incubated at $37^{\circ}C$ for 48 h, and then analyzed for various saccarides by HPLC. The results showed that changes in the concentrations of lactose and galactose were significantly decreased and increased, respectively (p<0.05), but all 3 probiotic strains tested in this study showed no increase in glucose concentration during 48 h of incubation. Both DH5 and BL720 showed high lactase activities (p<0.05), whereas BLC exhibited the lowest activity. Additionally, all three lactic acid bacteria showed high tagatose, but did not show high xylose and sedoheptulose. Finally, DH5, a kefir-isolated LAB, may have similar characteristics and properties to typical Bifidobacterium spp. and showed higher lactase activity than commercial Bifidobacterium spp.

• Food Science and Preservation
• /
• v.20 no.5
• /
• pp.636-642
• /
• 2013

Quality and sensory characteristics of tofu prepared with concentrated to 8 $^{\circ}Brix$ deep ground sea-like water (SW) were investigated to check the availability for coagulants. The tofu was coagulated with three kinds of commercially coagulant, such as $MgCl_2$, $CaSO_4$ and glucono-${\delta}$-lactone. Different amounts of SW and soybean milk were added: SW-20 g/L, SW-25 g/L and SW-30 g/L. The moisture content and pH were significantly lower in which preparation with glucono-${\delta}$-lactone coagulated tofu, and others has not significantly difference each other. The mineral contents in the coagulant influenced the mineral content of the tofu, which contained larger quantities of major minerals. However, the mineral content of the tofu was not affected of the mineral concentration in the coagulant. The L and b values of the tofu prepared with SW were not significantly different. The hardness of the tofu prepared with the commercial coagulants was significantly lower than that of the tofu produced with the SW. The sensory property was lower when the hardness was lower and higher. In conclusion, the quality characteristics of SW-prepared tofu were not significantly different from those of the tofu prepared with the commercial coagulants, but the texture and the taste of the SW-prepared tofu were excellent.

• Korean Journal of Food Science and Technology
• /
• v.20 no.2
• /
• pp.140-147
• /
• 1988

The pysicochemical and bacteriological properties of yogurts made by single or mixed cultures of L. bulgaricus FRI025 and S. thermophilus CHI were investigated. L. bulgaricus FRI025 which was isolated from raw milk was selected as starter culture among 22 strains of lactic culture by measuring viscosity, flavor, growth and acid production ability. The acid production and number of viable cell were increased by using L. bulgaricus FRI025 and S. thermophilus CHI together in ratio of apporximately 1:1. The pH, titratable acidity, viable cell number and viscosity of yogurt were 4.08, 1.14%, $2.5{\times}10^{10}/ml$ and 2100 cp after 9 hours incubation at $40^{\circ}C$, respectively. The pH and viable cell number were decreased on the other hand titratable acidity and viscosity were increased after 7 days of storage at $4^{\circ}C$. The changes of quality did not show significantly after storage. The selected starter was much higher than commercial yogurt starter in the acid production and growth of starter. The yogurt nanufactured with selected starter was better than with commercial yogurt in sensory evalution such as taste, texture, flavor and overall acceptability.

• Asian-Australasian Journal of Animal Sciences
• /
• v.18 no.2
• /
• pp.249-254
• /
• 2005

The objective of this study was to investigate effects of dietary level of CLA and the duration of feeding CLAcontaining diets on reproductive performance in sows and piglet growth rate. Tallow (3% in gestation diet and 5% in lactation diet, respectively) was incorporated as a fat source in control diet, and each 50% (dietary CLA level of 0.75% in gestation diet, and 1.50% in lactation diet, respectively) or 100% (dietary CLA level of 1.50% in gestation diet, and 2.50% in lactation diet, respectively) of tallow was replaced by a commercial CLA preparation containing 50% CLA isomers. Diets containing CLA were fed either from d 15 premating to weaning or d 74 post-mating to weaning. The level of dietary CLA and feeding duration did not affect litter size. High dietary level of CLA, however, decreased piglet weights at birth (p<0.01) and tended to decrease backfat thickness of sows at weaning. Longterm feeding of CLA-containing diets decreased piglet weights at weaning (p<0.05) and backfat thickness of sows at weaning (p<0.05). CLA supplemented in sow diet was transferred to fetus and piglets during pregnancy and nursing period, respectively. CLA contents of femoral muscle of piglets were 2.08 to 2.57 mg per g of fat at birth, and 2.36 to 4.47 mg at 10 days of age in CLA groups, while CLA was not detected in the control group. In conclusion, dietary supplementation of CLA tended to lower backfat thickness of sow and piglets' weight at birth or weaning, but did not affect total litter size. Dietary CLA was transferred efficiently during prenatal and postnatal periods of time through the placenta and milk, respectively.