• Animal Bioscience
• /
• 제34권12호
• /
• pp.1963-1973
• /
• 2021

Objective: The present study aimed to evaluate the influence of including L-glutamine along with glutamic acid as a supplement in weaned piglets' diets with and without whey powder. Methods: Two assays were carried out. A total of 40 piglets ([Landrace×Large White]×Pietrain) weaned at 24 days of age with an initial body weight of 6.6±0.6 kg were used in the first assay, and the following parameters were evaluated: growth performance, the incidence of diarrhea, morphometry, intestinal integrity, and hepatic glycogen index. The animals were then blocked into four groups according to different diets: diet all-grain feeding (G); diet all-grain feeding with whey powder (GW); and with vs without 1% supplementation of the commercial product containing L-glutamine and glutamic acid (A or NA). Whey powder was added according to the stage of life, corresponding to 17%, 10%, and 5%, respectively, in order to meet the need for lactose. The animals were evaluated at 24 to 42 days and at 24 to 55 days of age. The nutrient digestibility for the second assay was carried out by using 24 animals with an average weight of 11.49±1.6 kg, and the same diets were tested. Results: The supplementation of L-glutamine + glutamic acid or the addition of whey powder in diets for weaned piglets provided (p<0.05) greater feed intake, greater weight gain and improved feed conversion in the initial period (24 to 42 days age). However, in the whole period (24 to 55 days age) only amino acid supplementation affected (p<0.05) growth performance. There was a positive interaction (p<0.05) between the type of diet and L-glutamine + glutamic acid supplementation on villus height, crypt depth and the villus:crypt ratio in the duodenum. In addition, L-glutamine + glutamic acid supplementation reduced (p<0.05) the crypt depth and improved the villus:crypt ratio in the jejunum. The inclusion of whey powder affected (p<0.05) positively the digestibility coefficients analyzed except mineral matter digestibility coeficients. The supplementation of 1% the commercial product composed of L-glutamine and glutamic acid improved (p<0.05) only the digestibility coefficient of crude protein. Conclusion: These results indicate that supplementation of 1% commercial product containing L-glutamine + glutamic acid in diets for piglets from 24 to 55 days of age, dispenses with the use of whey powder when evaluating growth performance. Amino acid supplementation alone or associated with whey powder affects (p<0.05) positively the indicators of the intestinal integrity.

• 한국식품과학회지
• /
• 제23권4호
• /
• pp.471-477
• /
• 1991

치즈 제조시 생기는 유청을 reverse osmosis를 이용하여 농축한 후, 이로부터 유청음료를 제조하기 위한 최적조건을 조사하였다. 유당 가수분해도와 산생성은 Str. thermophilus와L. bulgaricus의 혼합균주가 Str. cremoris와 Str. lactis의 혼합균주에 비해 효율적이었다. 유청의 유당농축비율(LCR)이 증가할수록 적정산도는 증가하였으나 pH의 저하는 억제되었다. 원심침전량을 조사한 결과 LCR에 관련없이 모두 비슷한 수준이었으나 자연침전량의 경우 LCR 3.0 : 1은 침전이 거의 없었다. 안정제로서는 PGA가 가장 적합하였으며 LCR 3.0 : 1의 경우 0.l% 이하의 농도에서도 침전을 방지할 수 있었다. 감미료는 aspartame, 향료로는 yoghurt향이 가장 적합하였다.

• 한국균학회지
• /
• 제27권6호
• /
• pp.383-385
• /
• 1999

Cheese 제조시 부산물로 생성되는 whey를 배지로 사용하여 Aspergillus niger를 이용하여 citric acid를 생산하는데 영향을 미치는 여러 가지 요인 중 중요한 요인인 온도와 pH의 영향에 대하여 고찰하였다 15일간 27, 30, 33, $36^{\circ}C$와 pH 2, 3, 4, 5에서 각각 배양하면서 소비된 lactose의 양과 생산된 citric acid의 양을 측정하였다. 생산된 citric acid의 최대 농도는 33.9 g/l(구연산 생산에 쓰여진 유당을 기준으로 할 때 68.26%)이었으며, shaking speed는 citric acid 생산에 직접 영향을 주기보다는 pellet 형성시 그 형태에 영향을 미치는 것으로 나타났다. 배양 온도가 $33^{\circ}C$, pH는 3일때 가장 많은 양의 citric acid가 생산되었다.

• 환경정책연구
• /
• 제2권2호
• /
• pp.65-79
• /
• 2003

More than 145 million tons of liquid whey is produced world-wide as dairy processing waste per year, and half of it is discarded without proper treatment. Due to its high nutrient value, the environmental impact can be significant. Bioconversion of cheese whey can provide an effective way to reduce the waste and, at the same time, generate economically attractive value-added chemicals. In this study, cheese whey was fermented with P. acidipropionici to produce propionic acid which has a high market value for chemical and pharmaceutical industries. In order to specifically enhance propionic acid production, acetic acid production was suppressed using o-iodosobenzoic acid as an enzyme inhibitor. When grown in the presence of the inhibitor, propionic acid production rate increased by a factor of 2 while acetic acid production rate decreased by a factor of 3. Furthermore, when 0.3 mM of o-iodosobenzoic acid was used, the incipient stage(creeping growth period) was considerably reduced. Therefore, the inhibitor helps the cells begin to grow earlier and speed up the production of propionic acid. Although the production rate of propionic acid effectively increased, the final concentration(or production yield) remained unchanged due to product inhibition. Methods that can reduce product inhibition are being tested combined with o-iodosobenzoic acid to optimize both the production rate and yield. The results are expected to be informative for controlling the other byproducts for other applications.

• 한국식품영양학회지
• /
• 제18권2호
• /
• pp.109-114
• /
• 2005

[ $10\%$ ] 유청배지에 Lactobacillus acidophilus와 Propionibacterium freudereichii를 혼합 배양할 때 유청 발효물 중의 생균수의 변화, 유당 소모량, 프로피온산과 초산생성량 등을 측정하였고, 유청 발효물을 식빵 제조에 일정량 첨가하여 식빵의 부피, 조직감, 보존성 등을 분석하였다. 4일 배양동안 L. acidophilus의 생균수는 배양 36시간에 $2.4\ties10^9$ cfu/mL, P. freudenreichii는 배양 96시간에 $9.42\times10^8$ cfu/mL로 최대값을 나타냈고 L. acidophilus가 P. freudenreichii보다 빠르게 증식하였다. 유당의 소모율은 $87.5\%$이었고, 4일 배양 후 프로피온산은 18.5g/L, 초산은 4.8g/L 생성되었으며 그 비율은 3.8:1이었다. 식빵의 부피는 유청 발효물을 많이 첨가할수록 작았으나 조직감은 유청 발효물이 많이 첨가될수록 낮은 경도 값으로 부드럽게 나타났으며, 보존성은 유청 발효물을 $10\%$첨가하였을 때 대조구에 비하여 2일 이상의 효과가 있는 것으로 나타났다.

• Journal of Dairy Science and Biotechnology
• /
• 제35권4호
• /
• pp.249-254
• /
• 2017

The purpose of this study was to investigate the acid tolerance, bile acid tolerance, and fermentation activity of lactic acid bacteria isolated from Kimchi in the presence of hydrolysates of whey protein concentrate. Kimchi isolates DK109, DK119, DK121, DK128, DK211, DK212, and DK215, which were identified as Lactobacillus sp., and L. casei DK128 showed the highest acid and bile acid tolerance. To produce whey hydrolysates, enzymes were added to a 10% (w/v) whey protein concentrate (WPC) solution at 1:50 (w/v, protein). The viabilities of the DK strains were determined in the presence of low pH and bile salts. Then, yogurt was produced via fermentation with L. casei DK128, an isolate from Kimchi, in the presence of the following additives: CPP, WPC, and WPC hydrolysates (WPCH) generated by alcalase (A) or neutrase (N). The produced yogurts were subjected to various analyses, including viable cell counts (CFU/mL), pH, titratable activity, and sensory testing. After 8 h of fermentation, the pH and titratable activity values of all test samples were 4.2 and 0.9, respectively. The viable counts of LAB were $3.49{\times}10^8$, $5.72{\times}10^8$, $7.01{\times}10^8$, and $6.97{\times}10^8$, for the Control, CPP, A, and N samples, respectively. These results suggest that whey proteins have potential as dietary supplements in functional foods and that WPCH could be used in yogurt as a low-cost alternative to CPP.

• 한국축산식품학회지
• /
• 제42권3호
• /
• pp.504-516
• /
• 2022

This study aimed to investigate the effect on the chemical quality of whey and Ricotta obtained from ewes fed a red grape pomace (GP) dietary supplementation. The analyses were performed on whey, before and post Ricotta cheese-making, and in Ricotta after 1 (T1) and 5 (T5) d of ripening at 4℃. Moreover, fatty acid profile of whey before ricotta (WBR) cheese-making and Ricotta T1 of ripening and volatile profile of Ricotta T1 and T5 were investigated. The diet did not affect whey and Ricotta lipid content, conversely, significant variations were instead observed with regard to color. A lower amount of total phenolic compounds was found in WBR cheese-making, on the contrary, an opposite trend was highlighted in Ricotta T1 although no variations in antioxidant properties were detected. Moreover, GP modified fatty acid profile of whey and Ricotta but did not have any effect on protein profile of the main whey protein. The reduction of hexanal in Ricotta during the ripening suggest a better oxidative stability. The obtained results therefore suggested that the GP inclusion in the ewes diet, while modifying some chemical parameters, did not induce negative effects on the characteristics and quality of dairy by-products.

• Food Science and Biotechnology
• /
• 제16권5호
• /
• pp.836-842
• /
• 2007

In this study, we investigated the effects of heating ($80^{\circ}C$, 30 min) on the physicochemical and functional attributes of acid (cottage) and sweet (Edam and Cheddar) whey powders. The water holding capacity (WHC) of the whey powders was not affected by heating or pH value. The heated Cheddar whey powder had a significantly lower (p<0.05) WHC than that of the other wheys. Heating detrimentally impacted the emulsifying and foaming properties, On the other hand, heating significantly enhanced the heat stabilities (HS) of all powders, This was best demonstrated at the acidic pH values of 3.0 and 4.5, where the HS increased by 57 and 53, 181 and 167, and 31 and 48%, for the cottage, Edam, and Cheddar, respectively. Overall, this data provides useful insights into the manufacture of pasteurization and retort-stable whey powders.

• Journal of Microbiology and Biotechnology
• /
• 제28권9호
• /
• pp.1511-1516
• /
• 2018

In this study, we investigated Indole-3-acetic acid (IAA) production by a rice phylloplane bacteria, Enterobacter sp. DMKU-RP206, using sweet whey as a feed stock instead of lactose. We succeeded in using sweet whey for Enterobacter sp. DMKU-RP206 to produce 3,963.0 mg IAA/l with the optimal medium containing 1.48% sweet whey, 1.42% yeast extract and 0.88% $\text\tiny{L}$-tryptophan. The medium pH was adjusted to 6 and the culture conditions were shaking at 200 rpm on an orbital shaker at $30^{\circ}C$ for 3 days. We also evaluated the effect of IAA in culture filtrates of Enterobacter sp. DMKU-RP206 on the promotion of jasmine rice growth in a pot experiment. Compared with the negative control (without IAA), the result showed that biosynthetic IAA produced by Enterobacter sp. DMKU-RP206 significantly increased the growth of jasmine rice (Oryza sativa L. cv. KDML105) in terms of length and dry weight of shoot. This work thus reveals the impact of IAA produced by Enterobacter sp. on the promotion of jasmine rice growth.

• Biotechnology and Bioprocess Engineering:BBE
• /
• 제6권1호
• /
• pp.1-5
• /
• 2001

The potential use of spin filter device to retain Propionibacterium acidipropionici in the bioreactor under continuous mode of fermentation, and improve acid productivity, was examined. The yield of propionic acid based on lactose concentration was 51% in batch and 54% in continuous (dilution rate = 0.05 h(sup)-1) operation. The yield in continuous fermentation with cell retention using spin filter of 10 micron size (dilution rate = 0.05 h(sup)-1) was even higher at 70% (w/w). The volumetric productivity under batch and continuous mode of operation were 0.312g L(sup)-1 h(sup)-1 and 0.718g L(sup)-1 h(sup)-1 respectively. Continuous fermentation with cell retention demonstrated even higher volumetric productivities at 0.98g L(sup)-1 h(sup)-1 with out clogging problems. It could be used for utilization of cheese whey to produce propionic acid at higher yield and productivities.