【摘要】：魚(yú)鱗是有鱗魚(yú)類加工過(guò)程中產(chǎn)生的副產(chǎn)物,2008年我國(guó)淡水魚(yú)總產(chǎn)量1998萬(wàn)噸,其中有鱗魚(yú)1310萬(wàn)噸以上,每年大約可產(chǎn)生65萬(wàn)噸的魚(yú)鱗,除部分以原料形式出口于日本外,大部分未得到很好的開(kāi)發(fā)利用。目前國(guó)內(nèi)已開(kāi)展魚(yú)鱗酶解工藝研究,且多采用大酶量、長(zhǎng)酶解時(shí)間及恒定pH等技術(shù)來(lái)獲取較高的得率和水解度,從而導(dǎo)致產(chǎn)物苦味較重、鹽分含量過(guò)高,在工業(yè)化生產(chǎn)中不得不進(jìn)行脫苦、脫鹽處理。本課題以魚(yú)鱗為對(duì)象,在分析不同儲(chǔ)藏時(shí)間及不同魚(yú)種的魚(yú)鱗基本成分變化的基礎(chǔ)上,研究了水解條件和預(yù)處理方式對(duì)魚(yú)鱗酶解效果的影響,評(píng)價(jià)了三種蛋白酶酶解進(jìn)程中酶解產(chǎn)物的功能特性,建立了分步酶解法制備高抗氧化活性的魚(yú)鱗膠原肽的生產(chǎn)工藝。主要研究?jī)?nèi)容和結(jié)果如下： (1)魚(yú)鱗原料的確定。測(cè)定了儲(chǔ)藏0.5～4年的草魚(yú)和鰱魚(yú)鱗及五種淡水魚(yú)(草魚(yú)、鯽魚(yú)、鯉魚(yú)、鰱魚(yú)和鳊魚(yú))魚(yú)鱗的基本成分。儲(chǔ)藏時(shí)間對(duì)魚(yú)鱗的膠原蛋白含量影響不大,草魚(yú)、鳊魚(yú)及鰱魚(yú)鱗中膠原蛋白含量較高,且草魚(yú)鱗片較大便于收集,故選擇存放0.5年的干草魚(yú)鱗為研究對(duì)象進(jìn)行后續(xù)酶解實(shí)驗(yàn)。 (2)水解條件的確定。起始pH值、熱處理溫度、熱處理時(shí)間、底物濃度、加酶量對(duì)草魚(yú)鱗水解產(chǎn)物的水解度和氮收率均有顯著影響(p0.01)。堿性蛋白酶水解草魚(yú)鱗的適宜條件為：料液比1：17,熱處理溫度85℃,熱處理時(shí)間1.5h,起始pH值8.0～8.5,加酶量420u/gpro,在60℃水解4.5h。中性蛋白酶和復(fù)合蛋白酶水解草魚(yú)鱗的適宜條件為：料液比1：17,熱處理溫度85℃,熱處理時(shí)間1.5h,起始pH值7.0～7.5,加酶量450u/gpro,在50℃水解4.5h。 (3)草魚(yú)鱗的預(yù)處理方式的確定。預(yù)處理對(duì)草魚(yú)鱗酶解產(chǎn)物的氮收率、水解度和氨基酸生成量有顯著影響(p0.01)。在粉碎-熱處理、不粉碎-熱處理、不粉碎-不熱處理等三種處理方式中,粉碎-熱處理的草魚(yú)鱗的酶解產(chǎn)物的氮收率、水解度和氨基酸生成量均最高。預(yù)處理對(duì)魚(yú)鱗的復(fù)合蛋白酶和中性蛋白酶酶解產(chǎn)物抗氧化活性影響不大,而對(duì)魚(yú)鱗的堿性蛋白酶酶解產(chǎn)物的抗氧化活性有明顯影響。對(duì)于堿性蛋白酶酶解產(chǎn)物而言,不粉碎-不熱處理魚(yú)鱗的酶解產(chǎn)物的抗氧化活性最強(qiáng)(DPPH清除率的IC50值最小),但其氮收率僅71%,遠(yuǎn)低于經(jīng)粉碎和加熱處理魚(yú)鱗的酶解產(chǎn)物的氮收率的(99%左右)。預(yù)處理方式對(duì)酶解產(chǎn)物分子量分布的影響不明顯。 (4)酶解進(jìn)程中產(chǎn)物特性的研究。三種蛋白酶水解產(chǎn)物的氮收率、水解度、游離氨基酸、乳化活力指數(shù)(ESI)及抗氧化活性隨酶解時(shí)間的延長(zhǎng)其變化規(guī)律相似。酶解時(shí)間為0～4h,其氮收率、水解度、游離氨基酸及DPPH自由基清除率呈增大趨勢(shì),ESI和分子量呈減小趨勢(shì)。酶解超過(guò)4h后繼續(xù)延長(zhǎng)酶解時(shí)間,堿性蛋白酶、復(fù)合蛋白酶和中性蛋白酶水解液氮收率分別維持在97%、97%、90%左右,而DPPH自由基清除率呈下降趨勢(shì),產(chǎn)物分子量分布無(wú)明顯變化。 (5)兩步酶解法制備抗氧化肽。堿性蛋白酶與風(fēng)味蛋白酶分步酶解草魚(yú)鱗的水解產(chǎn)物水解度和氨基酸生成量最高,當(dāng)總酶活為840 u/gpro時(shí),其水解度和氨基酸生成量分別為15%和130mg/g魚(yú)鱗。水解產(chǎn)物的DPPH自由基清除率隨總酶活的增加而升高,當(dāng)總酶活高于525 u/gpro時(shí),堿性蛋白酶與復(fù)合蛋白酶分步酶解產(chǎn)物的DPPH自由基清除率最高。在總酶活為840u/gpro時(shí),堿性蛋白酶與復(fù)合蛋白酶分步酶解產(chǎn)物的平均分子量最小,其中分子量高于9952Da的多肽含量?jī)H占14%,且5946Da以下的多肽占多肽總量的1/2左右。
[Abstract]:Fish scale is the by-product produced during the process of fish scale fish. In 2008, the total output of freshwater fish in China was 1998 million tons. Among them, there were more than 13.1 million tons of scale fish, about 65 million tons of fish scale can be produced every year, and most of the fish scales were exported to Japan in the form of raw materials, and most of them were not well developed and developed. At present, fish scale enzymatic hydrolysis technology has been carried out in China, and the high yield and degree of hydrolysis can be obtained by adopting the technology of large enzyme amount, long enzymolysis time and constant pH value, so that the bitter taste of the product is heavy, the content of salt is too high, and the debittering and desalting treatment of the fish scale enzyme solution has to be carried out in industrial production. Based on the analysis of the changes of fish scales in different storage times and different species, the effects of hydrolysis conditions and pretreatment on the enzymatic hydrolysis of fish scales were studied. A process for preparing fish scale collagen peptide with high antioxidant activity by stepwise enzymatic hydrolysis was established. The main contents and results are as follows: (1) fish scale raw material Determination of fish scales of grass carp and fish scales and five freshwater fishes (grass carp, Carassius auratus, Cyprinus carpio, sturgeon and sturgeon) for 0. 5 ~ 4 years were determined. The content of collagen in fish scale was not big, but the content of collagen in grass carp, sturgeon and fish scale was higher, and the fish scale of grass was more convenient to collect, so it was chosen to store 0. 5 years' hay scale was the research object for follow-up enzymolysis. Experiment. (2) Hydrolysis The conditions were determined. The initial pH value, heat treatment temperature, heat treatment time, substrate concentration, enzyme addition amount had significant influence on the hydrolysis degree and the nitrogen yield of the fish scale hydrolysate (p The optimum conditions are: the ratio of the liquid to the fish scale is 1: 17, the heat treatment temperature is 85.d egree. C., the heat treatment time is 1. 5h, the initial pH value is 8.0-8.5, the enzyme amount is 420u/ gro, The optimum conditions were: the ratio of liquid to liquid was 1: 17, the heat treatment temperature was 85 鈩，

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