• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.3
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• pp.321-326
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• 2016

The objective of this study was to obtain data on safety-in-use of yeast hydrolysate with a molecular weight of 10~30 kDa as a dietary supplement by assessing its subacute oral toxicity in ovariectomized rats. Yeast hydrolysate did not produce mortality or significant changes in general behavior or gross appearance of internal organs of rats. There were no significant differences in organ weights between control and yeast hydrolysate groups. Hematological analysis and blood chemistry revealed no toxic effects of yeast hydrolysate. Neither gross abnormalities nor histopathological changes were observed. These results show that yeast hydrolysate possesses very low toxicity as indicated in a postmenopausal animal model.

• Preventive Nutrition and Food Science
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• v.14 no.2
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• pp.123-128
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• 2009

This study was conducted to evaluate the weight reduction effect of yeast hydrolysate-SR101. Thirty female college students participated in a 6 week weight control program. All subjects were randomly assigned to either the placebo group, YH-SR101 (yeast hydrolysate-SR101) group, or eX diet (product of yeast hydrolysate-SR101) group. The mean energy intake of the placebo group was 1445.2${\pm}$364.0 kcal (carbohydrate: 60.1%, protein: 25.6%, fat: 14.3%), while those of the YH-SR101 and the eX diet group were 1505.6${\pm}$296.2 kcal (carbohydrate: 60.5%, protein: 22.2%, fat: 14.8%) and 1353.8${\pm}$326.3 kcal (carbohydrate: 63.2%, protein: 20.9%, fat: 15.9%), respectively. The placebo group lost 0.19${\pm}$1.14 kg of body weight, while the treatment groups (YH-SR101 and eX diet) lost 1.13${\pm}$0.83 and 1.54${\pm}$0.74 kg of body weight, respectively. There were significant differences in the decrease in body weight between the placebo and the treatment group (p<0.05). There were also significant differences in the decrease in fat mass between the placebo and treatment group (p<0.05). Furthermore, the BMI of the YH-SR101 and the eX diet groups also differed significantly before and after the diet program (p<0.05). Additionally, the BMI and waist size reduction of the treatment groups (YH-SR101 and eX diet group) differed significantly when compared to the placebo (p<0.05). The reduction of the resting metabolic rate (RMR) blood glucose, total-cholesterol, HDL-cholesterol, LDL-cholesterol and triglyceride did not differ significantly among groups. Taken together, these findings indicate that consumption of yeast hydrolysate-SR101 and eX Diet may lead to decreased body weight and fat.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.105-108
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• 2003

To enhance the performance of a serum-free medium (SFM) for human thrombopoietin (hTPO) production in suspension cultures of recombinant Chinese hamster ovary (rCHO) cells, several low-cost hydrolysates such as yeast hydrolysate (YH), soy hydrolysate, wheat gluten hydrolysate and rice hydrolysate were tested as medium additives. Among various hydrolysates tested, the positive effect of YH on hTPO production was most significant. When 5 g/L YH was added to SFM, the maximum hTPO concentration in batch culture was 40.41 ${\mu}g/mL$, which is 11.5 times higher than that in SFM without YH supplementation. This enhanced hTPO production in YH-supplemented SFM was obtained by the combined effect of enhanced $q_{hTPO}$ and increased culture longevity. In addition YH supplementation did not affect in vivo biological activity of hTPO. Taken together, the results obtained demonstrate the potential of YH as a medium additive for hTPO production in serum-free suspension cultures of rCHO cells.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.5
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• pp.1000-1003
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• 2001

A yeast hydrolysate SCP-20 with anti-stress and mitigative effects for premenstrual syndromes (PMS) was composed with crude protein (57.5%) and carbohydrates (28.1%). For the investigation of anti-stress effect in the immobilization stressed rats, the weights of spleen, thyroid and kidney in the group of SCP-20 sdministration were significantly different from those in the group not given SCP-20. Total power (TP), suppression indicator of stress, was obtained from frequency of heart rate variability. TP was changed by the administration of SCP-20 suggesting that SCP-20 has the autonomous nervous control effect. In premenstrual assessment form(PAF), the administration of SCP-20 reduced the intensity of somatic symptoms, emotional symptoms, and behavioral symptoms.

• Preventive Nutrition and Food Science
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• v.20 no.4
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• pp.284-291
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• 2015

In this study, we attempted to enrich cyclo-His-Pro (CHP) using enzymatic hydrolysis of yeast and to evaluate the functionality of yeast hydrolysate (YH)-enriched CHP. Flavourzyme offered a better performance in enhancing CHP content than other proteases. The CHP enrichment conditions were optimized as follows: addition of 1% Flavourzyme, 48-h incubation at 60oC, and pH 6.0. The CHP content significantly increased by 20-fold after ultra-filtration (UF). Maximal CHP translation was obtained after heating for 8 h at 50oC and pH 7.0. YH showed poor foaming capacity between pH 3.0 to 9.0. The emulsifying activities of YHs were slightly higher at near acidic pH. Increase in heating temperature and time resulted in decreased CHP content. The results indicate that YH is more heat stable after UF. Therefore, the CHP in YH after UF can be used as a food additive with physiological CHP activity and high heat stability.

• KSBB Journal
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• v.19 no.4
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• pp.245-249
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• 2004

A combined method of autolysis and enzymatic hydrolysis of baker's yeast was developed for the production of yeast extract, which is widely used as a natural food ingredient. From statistical analysis, NaCl and ethanol addition were found to be significantly effective factors in autolysis of yeast. The optimum dosages of salt and ethanol were 3% and 1%, respectively. Heat treatment and the use of cell lytic enzyme were not significantly effecting on the autolysis. Yeast hydrolysate was prepared by autolysis, followed by enzymatic hydrolysis using proteases, nuclease and deaminase. Additionally, the hydrolysate was processed by downstream process including Maillard reaction and debittering. The total dry matter yield and total nitrogen yield for the process were 76% and 59%, respectively. Compared to a process using brewer's yeast, when baker's yeast was used as a raw material, a higher recovery yield was obtained.

• KSBB Journal
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• v.25 no.4
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• pp.401-407
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• 2010

We established a strategy for bioethanol production using the hydrolysate of rape stem, in which the inhibitor cocktail was added intentionally. The final goal of this study was to circumvent the detoxification process when the hydrolysate of lignocelluloisic biomass contained the toxic substances in high concentration. When six yeast strains were examined, Sacchromyces cerevisiae ATCC 96581 and Pichia stipitis CBS 7126 were relatively resistant to inhibitor cocktail. Then, using strains 96581 and 7126, we designed a process strategy for bioethanol production, assuming that the concentration of toxic substance in the hydrolysate of rape stem was remarkably high. When strains 96581 and 7126 were inoculated simultaneously, it was observed that strain 7126 produced bioethanol as well as strain 96581, although the concentration of inhibitor cocktail was 18.2% (v/v). Finally, throughout this co-cultivation of strains 96581 and 7126, bioethanol was produced about 6.0 (g/L), and bioethanol yield reached at 0.4 (g-bioethanol/g-reducing sugar) (78.4% of theoretical value).

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.10
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• pp.1565-1572
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• 2019

Objective: This study was aimed to investigate the effects of brewer's yeast hydrolysate (YH) on growth performance, nutrients digestibility, blood profiles and meat quality of growing pigs. Methods: A total of 200 growing pigs ($[Landrace{\times}Yorkshire]{\times}Duroc$) (initial body weight, $25.31{\pm}1.29kg$) were allotted to 5 treatments as follow: CON, basic diet; and YH treatment, CON+0.05%, 0.1%, 0.5%, and 1.0% of YH, respectively. Results: On wk 11, 16 and overall phase, pigs fed YH diet showed a linear improvement in average daily body gain and gain/feed (p<0.05). The pigs that received YH linearly increased the digestibility of dry matter, nitrogen, and energy on wk 11 and 16. The concentration of serum urea nitrogen was linearly increased in YH treatments on wk 16. However, the carcass weight, back fat and lean muscle percentage of pigs receiving YH had no significant change. Besides, no difference was observed in creatinine and total protein in the blood among treatments. Conclusion: The pigs fed a graded YH diet had improved growth performance and nutrient digestibility, meanwhile, the YH increased the serum urea nitrogen in the growing pigs.

• Journal of Microbiology and Biotechnology
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• v.21 no.1
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• pp.109-114
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• 2011

In this study, we investigated the feasibility of producing bioethanol from the hydrolysate of rape stem. Specifically, the most ideal yeast strain was screened, and the microaeration was performed by surface aeration on a liquid medium surface. Among the yeast strains examined, Pichia stipitis CBS 7126 displayed the best performance in bioethanol production during the surface-aerated fermentor culture. Pichia stipitis CBS 7126 produced maximally 9.56 g/l of bioethanol from the initial total reducing sugars (about 28 g/l). The bioethanol yield was 0.397 (by the DNS method). Furthermore, this controlled surface aeration method holds promise for use in the bioethanol production from the xylose-containing lignocellulosic hydrolysate of biomass.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.2
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• pp.451-454
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• 2004

A total of forty male mice (32∼33 g average initial body weight) were used in a 10-d growth study to evaluate the effects of dietary yeast hydrolysate SCP-20 on reproductive function in male mice. Dietary treatments included 1) CON (basal diet) and 2) TRT (CON diet +1.5% yeast hydrolysate SCP-20). Testis weight of male mice fed TRT diets was higher than that of male mice fed CON diet (p<0.05). Also VSL was significantly (p<0.05) increased in male mice fed TRT diet compared to that in male mice fed CON diet. Male mice fed TRT diet showed significant (p<0.05) improvement in VAP (average-path velocity) and LIN (linearity) compared to male mice fed CON diet. Also, velocity of epididymal sperm of male mice fed TRT diets was higher than that of male mice fed CON diet (P<0.05). In conclusion, the results obtained from this trial suggests that the dietary yeast hydrolysate SCP-20 was an effective means of improving sperm velocity in male mice.