• The Korean Journal of Food And Nutrition
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• v.7 no.2
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• pp.128-136
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• 1994

Mackerel muscle protein hydrolysates, which were prepared from defatted mackerel meal by proteases such as complex enzyme, alcalase, bromelain, pancrease, pepsin, w-chymotrypsin, trypsin and papain, were tested for the antioxidative action against linoleic acid. Among proteases tested, the hydrolysates obtained from the treatment of complex enzyme, bromelain and alcalase showed higher antioxidative effects. Also, the hydrolysates showed the synergistic effects with o-tocopherol and the inhibitory effects for peroxidation of metal ions(Fe3+, Cua+) From the profiles of fractionation of the hydrolysates with Bio-gel P-2 column, the most active fractions, part I(complex enzyme-derived) and part e(bromelain-derived), had below MW 1,400 and the antioxidative effects were closely related to the binding capacity with metal ion(Cua+). Amno acid composition of the part I was abundant in histidine, arginine, phenylalanine and lysine, and the part e was abundant in lysine, glutamic acid and leucine.

• Journal of the East Asian Society of Dietary Life
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• v.19 no.1
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• pp.45-51
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• 2009

In this study, food protein hydrolysates were prepared from six types of food protein: purified meat protein, whole egg protein, casein, isolated soy protein, concentrated rice protein, and gluten. Food proteins were hydrolyzed with pepsin and ethanol (80%)-soluble fractions of pepsin hydrolysates were employed for analysis. The products were colorless and odorless powders with low fat content and good solubility. The MW (molecular weight) of the protein hydrolysates was confirmed to be $200{\sim}1,800$ via gel filtration. Free amino acid contents accounted for less than 5% of the samples. The results of our amino acid analysis revealed that all food protein hydrolysates preserved their original amino acid compositions and nutritional values of their source proteins with highly pure oligopeptide mixtures. These results show that the food protein hydrolysates prepared in these investigations should prove excellent dietary nitrogen sources for a variety of applications.

• Journal of Life Science
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• v.10 no.5
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• pp.436-446
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• 2000

This study was conducted to investigate the effects of different dietary enzymatic hydrolysates using squid and mackerel by-product on feed efficiency, growth and chemical composition in Korean rockfish (Sebastes schlegeli) after a eight weeks feeding experiment. Effects on the weight gain and feed efficiency in the enzymatic hydrolysates added groups were very effective. Weight gain were significantly higher in the squid hydrolysates whole added group than in the other groups. Moisture and crude ash contents of muscle were not significantly affected by hydrolysates supplementation in all groups. Crude protein and lipid contents of muscle were increased after eight weeks feeding trial. Amino acid contents of muscle were higher in squid hydrolysates whole added group than in the other groups. Amino acids were not affected by hydrolysates supplementation in all groups. Fatty acid contents of muscle were increased after eight weeks growth trial. Fatty acids were not significantly different in the dietary groups.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.5
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• pp.1004-1009
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• 2001

Acid hydrolysates of cocoon was gained by acid hydrolysis of 2 N HCl, 11$0^{\circ}C$, 48 hours, neutralization and desalting from the cocoon. The amino acid compositions of acid hydrolysates of cocoon were glycine 43.25%, alanine 34.39%, serine 10.05% and valine 2.44%. The contents of essential amino acid was 10.05%. Food efficiency ratio of acid hydrolysates of cocoon group was equal to the reference protein, casein. Liver weight, GOT, GPT activity, serum albumin and serum total protein level of rats were not significantly different among the experimental groups. Therefore, the protein acid hydrolysates of cocoon is not of high quality. When the rat fed with high cholesterol, high lipid, and high sucrose diet was administered with 5% acid hydrolysates of cocoon, its plasma lipids concentration of acid hydrolysates of cocoon was favorably affected: its triglyceride was decreased, and the level of phospholipid and HDL cholesterol were increased. There was also an unfavorable effect: the levels of LDL cholesterol and total cholesterol went up. Therefore, the acid hydrolysates of cocoon is not a good protein food source, but is can be used a cosmetic, medical, or packing material. Further research will reveal how it will affect or improve plasma lipid.

• Journal of agriculture & life science
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• v.50 no.1
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• pp.155-165
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• 2016

The study investigated the effects of adding bovine plasma protein(PP) hydrolysates on the quality properties of cooked pork patties. Pork patties were prepared as follows: manufactured with pork back-fat(control); replacement of back-fat with 40% olive oil(T1), 40% olive oil and 2% PP hydrolysates(T2), and 40% olive oil and 4% PP hydrolysates(T3). The olive oil modified the fatty acid profiles of the pork patties by lowering the saturated fatty acids(SFAs) percentage. Olive oil and 4% PP hydrolysates addition reduced the level of 2-thiobarbituric acid-reactive substance(TBARS) values in pork patties, compared to the controls. Furthermore, the pork patties with added PP hydrolysates had higher pH values than the control. All samples containing olive oil and PP hydrolysates had increased levels of DPPH radical scavenging activity. In particular, added PP hydrolysates were more effective in increasing antioxidant activity than were the other treatments. Therefore, PP hydrolysates could be used as a natural antioxidative in cooked pork patties.

• Food Science of Animal Resources
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• v.34 no.2
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• pp.192-199
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• 2014

The effects of adding mechanically deboned chicken (MDC) hydrolysates on the quality characteristics of imitation crab stick (ICS) during storage were investigated. ICS was prepared from Alaska Pollack, chicken breast surimi, and protein hydrolysates enzymatically extracted from MDC. ICS samples were divided into 4 groups: without protein hydrolysate (control), added with 0.5% protein hydrolysate (T1), added with 1.0% protein hydrolysate (T2), and added with 1.5% protein hydrolysate (T3). Results showed that crude protein content did not differ significantly among the ICS samples (p>0.05). ICS sample added with MDC hydrolysates had higher crude fat and ash content but lower moisture content than the control (p<0.05). Lightness was significantly lower in T2 and T3 than in the other groups at 0 and 4 wk of storage. Also, whiteness decreased in the groups contained MDC hydrolysates. Breaking force and jelly strength were higher in samples containing MDC hydrolysates compared to control samples (p<0.05). Additionally, saturated fatty acid contents were lower in the groups containing MDC hydrolysates than in control sample groups (p<0.05). Polyunsaturated fatty acid (PUFA) and essential fatty acids (EFA) were significantly higher in T2 and T3 than the control samples. In particular, all samples containing MDC hydrolysates had reduced thiobarbituric acid-reactive substances (TBARS) values at 4 wk. Free radical scavenging activity also was increased with addition of MDC hydrolysates.

• Journal of Microbiology and Biotechnology
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• v.32 no.11
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• pp.1479-1484
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• 2022

Bacterial cellulose (BC) is gaining attention as a carbon-neutral alternative to plant cellulose, and as a means to prevent deforestation and achieve a carbon-neutral society. However, the high cost of fermentation media for BC production is a barrier to its industrialization. In this study, chestnut shell (CS) hydrolysates were used as a carbon source for the BC-producing bacteria strain, Gluconacetobacter xylinus ATCC 53524. To evaluate the suitability of the CS hydrolysates, major inhibitors in the hydrolysates were analyzed, and BC production was profiled during fermentation. CS hydrolysates (40 g glucose/l) contained 1.9 g/l acetic acid when applied directly to the main medium. As a result, the BC concentration at 96 h using the control group and CS hydrolysates was 12.5 g/l and 16.7 g/l, respectively (1.3-fold improved). In addition, the surface morphology of BC derived from CS hydrolysates revealed more densely packed nanofibrils than the control group. In the microbial BC production using CS, the hydrolysate had no inhibitory effect during fermentation, suggesting it is a suitable feedstock for a sustainable and eco-friendly biorefinery. To the best of our knowledge, this is the first study to valorize CS by utilizing it in BC production.

• Journal of Microbiology and Biotechnology
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• v.29 no.2
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• pp.256-267
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• 2019

The use of low-cost substrates represents one key issue to make single cell oil production sustainable. Among low-input crops, Arundo donax L. is a perennial herbaceous rhizomatous grass containing both C5 and C6 carbohydrates. The scope of the present work was to investigate and optimize the production of lipids by the oleaginous yeast Cutaneotrichosporon curvatus from undetoxified lignocellulosic hydrolysates of steam-pretreated A. donax. The growth of C. curvatus was first optimized in synthetic media, similar in terms of sugar concentration to hydrolysates, by applying the response surface methodology (RSM) analysis. Then the bioconversion of undetoxified hydrolysates was investigated. A fed-batch process for the fermentation of A. donax hydrolysates was finally implemented in a 2-L bioreactor. Under optimized conditions, the total lipid content was 64% of the dry cell weight and the lipid yield was 63% of the theoretical. The fatty acid profile of C. curvatus triglycerides contained 27% palmitic acid, 33% oleic acid and 32% linoleic acid. These results proved the potential of lipid production from A. donax, which is particularly important for their consideration as substitutes for vegetable oils in many applications such as biodiesel or bioplastics.

• Korean Journal of Poultry Science
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• v.36 no.4
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• pp.311-316
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• 2009

The study was conducted to evaluate the effects of dietary acid hydrolysates of cocoon on laying performance, egg quality, blood level of immune substance and cholesterol in laying hens. The animals used in the experiment were a total of 240 Hy-Line Brown laying hens (41 weeks old). Dietary treatments included 1) CON (basal diet), 2) SP1 (basal diet + acid hydrolysates of cocoon 0.05%), 3) SP2 (basal diet + acid hydrolysates of cocoon 0.1%) and 4) SP3(basal diet + acid hydrolysates of cocoon 0.2%) twelve laying hens were allotted to a block (pen) with five replicated. Through the whole period of experiment, egg production, egg weight, egg shell breaking strength and egg shell thickness were no significant difference. However, acid hydrolysates of cocoon treatments (SP1, SP2, SP3) significantly increase their egg yolk height and Haugh unit compared to control (P<0.05). IgG and WBC (white blood cell) contents in blood were higher in SP1, SP2, SP3 treatment compared to control (P<0.05). However, albumin and total protein content in blood were no significant difference. Phospholipid, HDL-cholesterol, LDL-cholesterol and total cholesterol contents in serum were higher in SP1, SP2, SP3 treatment compared to control (P<0.05). In conclusion, supplement dietary acid hydrolysates of cocoon improved egg yolk height, Haugh unit, and blood level of phospholipid, HDL-cholesterol, LDL-cholesterol, total cholesterol in laying hen.