• 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.

• 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.

• Microbiology and Biotechnology Letters
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• v.30 no.1
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• pp.39-45
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• 2002

It was found that the peptides originated from the hydrolysates of silk fibroin have in vitro immunostimulating effects in murine macrophage RAW264.7 cells. The stimulation effects on nitric oxide (NO) production resulted from treatments of acid or enzymatic hydrolysates were measured. The silk fibroin preparation isolated from cocoon was most efficiently digested by acid hydrolysis. Even though the sole treatment of acid hydrolysate stimulated the NO production in dose-dependent pattern, a part of its activity was found to be caused by the contaminated endotoxin, LPS. When each endotoxin-free hydrolysates obtained by filtering it through an ultrafiltration membrane of molecular weight (MW) cut-off 10,000 to eliminate LPS was used, the peptic hydrolysate with lowest degree of hydrolysis showed the highest activity. The fractions of peptic hydrolysate with MW ranges of 1,000∼10,000, 500∼1,000 and below 500 also showed a higher MW-higher activity correlation. From the analyses of amino acid composition of each hydrolysate, it was found that the contents of arginine, lysine, alanine and glycine residues affected the activity level of hydrolysate. The results of this study showed a possibility of utilizing fibroin as a source for immunostimulating (chemopreventive) functional peptides.