رسالة جامعية
Utilization of wastes from Pacific whiting surimi manufacturing : proteinases and protein hydrolysate
| العنوان: | Utilization of wastes from Pacific whiting surimi manufacturing : proteinases and protein hydrolysate |
|---|---|
| المؤلفون: | Benjakul, Soottawat |
| المساهمون: | Morrissey, Michael T., Hansen, E. M., Gamble, W., Wroldstad, Ronald E., Food Science and Technology, Oregon State University. Graduate School |
| بيانات النشر: | Oregon State University |
| المجموعة: | ScholarsArchive@OSU (Oregon State University) |
| مصطلحات موضوعية: | Surimi, Proteinase -- Recycling, Fisheries -- By-products -- Recycling, Pacific hake, Protein hydrolysates -- Recycling |
| الوصف: | Both liquid and solid wastes from Pacific whiting surimi manufacturing were characterized and value-added products were recovered. A proteinase in surimi wash water (SWW) was determined to be cathepsin L with Mr 54,200 on SDS-substrate gel. Heat treatment and acidification shifted the activity zone to M [subscript r] 39,500. No evidence of calpain, cathepsin B or H activity was found. Cathepsin L from SWW was recovered by ohmic heating (55°C for 3 min), ultrafiltration, and freeze-drying with overall yield of 0.83 g protein/L SWW and 78% recovery of activity. A 5.9 purification fold was achieved by these processes. The recovered enzyme had an optimum activity at pH 4.0 and showed preferable hydrolytic activity towards casein, acid-denatured hemoglobin and myofibrils. β-Mercaptoethanol, dithiothreitol and urea enhanced the enzyme activity. The recovered proteinase showed 18.5% residual activity after 7 wk storage at 4°C. Proteolytic activity in solid waste and digestive organs from Pacific whiting was investigated. Pepsin-like proteinase predominated in solid waste, while trypsin-like proteinase was predominant in viscera. Carboxypeptidase b was found in both viscera and solid waste. Protein hydrolysate was produced from Pacific whiting solid waste (PWSW) using commercial proteinase, Alcalase, under optimum hydrolysis conditions. Enzyme concentration, reaction time and waste/buffer ratio affected the hydrolysis and nitrogen recovery (NR). Correlation between the degree of hydrolysis (DH) and NR was high (R₂=0.978). Freeze-dried hydrolysate contained 79.97% protein and showed similar amino acid composition to PWSW and Pacific whiting muscle but tryptophan was reduced. With different DH (20, 30, 40, 50, 60%), surface hydrophobicity, total and surface sulfhydryl content decreased as the DH increased. The hydrolysate showed a high solubility over a wide pH range. Fat adsorption and fat binding capacity were reduced, while foam expansion was enhanced with an increased DH. Hydrolysate with DH of 30% showed highest ... |
| نوع الوثيقة: | doctoral or postdoctoral thesis |
| اللغة: | English unknown |
| العلاقة: | https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/8049g871zTest |
| الإتاحة: | https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/8049g871zTest |
| حقوق: | Copyright Not Evaluated |
| رقم الانضمام: | edsbas.29223FCA |
| قاعدة البيانات: | BASE |
| الوصف غير متاح. |