Food-derived protein hydrolysates and peptides:anxiolytic and antidepressant activities,characteristics,and mechanisms

Globally,the prevalence of anxiety and depression has reached epidemic proportions.Food-derived protein hydrolysates and peptides delivered through dietary supplementation can avoid the negative risks associated with traditional pharmaceuticals while delivering superior anxiolytic and antidepressant effects.This review summarizes current research on food-derived anxiolytic and antidepressant protein hydrolysates and peptides,and subsequently analyses their physicochemical characteristics and elaborates on their mechanisms.The aim of this work is to contribute to the in-depth study and provide a theoretical foundation for the development of related products to better serve patients with anxiety and depression.

Preparation,characterization and antioxidant activity analysis of three Maillard glycosylated bone collagen hydrolysates from chicken,porcine and bovine

Bone collagen hydrolysates(peptides)derived from byproduct of animal product processing have been used to produce commercially valuable products due to their potential antioxidant activity.Maillard glycosylated reaction is considered as a promising method to enhance the antioxidant activity of peptides.Hence,this research aims at investigating the Maillard glycosylation activity and antioxidant activity of bone collagen hydrolysates from different sources.In this study,3 glycosylated bone collagen hydrolysates were prepared and characterized,and cytotoxicity and antioxidant activity were analyzed and evaluated.The free amino groups loss,browning intensity,and fluorescence intensity of G-Cbcp(glycosylated chicken bone collagen hydrolysates(peptides))were the heaviest,followed by G-Pbcp(glycosylated porcine bone collagen hydrolysates(peptides))and G-Bbcp(glycosylated bovine bone collagen hydrolysates(peptides)).The results of amino acid analysis showed that amino acid composition of different bone collagen hydrolysates was significantly different and the amino acid decreased to different degrees after Maillard glycosylated reaction,which may lead to differences in Maillard glycosylated reaction activity.Furthermore,the 3 glycosylated hydrolysates showed no significant cytotoxicity.The results showed that glycosylation process significantly increased the antioxidant activity of bone collagen hydrolysates,and G-Cbcp showed the strongest antioxidant activity,followed by G-Pbcp and G-Bbcp.Therefore,compared with the bone collagen hydrolysates,3 glycosylated hydrolysates showed significant characteristic and structural changes,and higher antioxidant activity.

The efficiency and safety evaluation of hemoglobin hydrolysate as a non-heme iron fortifier

Hemoglobin hydrolysate is derived from the enzymatic degradation of hemoglobin.This work aimed to evaluate whether hemoglobin hydrolysate promotes the absorption of non-heme iron and the safety of absorbed iron in mice by analyzing the iron binding content,iron circulation,and liver homeostasis.We found that hemoglobin hydrolysate promoted the absorption of non-heme iron with high efficiency in duodenum by spontaneously binding non-heme iron during digestion,and increased hepatic iron content by up-regulating divalent metal transporter 1,zinc transporter 14,but hepatic iron content only increased at 3 weeks.Duodenal iron entered the blood through ferroportin without restriction at 3 weeks,and excessive iron entered the liver and then affected the hepatocyte membranes permeability and lipid synthesis through oxidative stress.With the prolongation of dietary intervention,the up-regulated hepcidin acted on the ferroportin to restrict excess iron from entering the blood,and then the hepatic homeostasis recovered.In addition,hemoglobin hydrolysate enhanced the hepatic antioxidant capacity.Taken together,hemoglobin hydrolysate has a strong ability to promote the absorption of non-heme iron in vivo,and the absorbed iron is relatively safe due to the regulation of hepcidin.

Antihypertensive effects of whey protein hydrolysate involve reshaping the gut microbiome in spontaneously hypertension rats

Novel angiotensin-converting enzyme(ACE)inhibitory peptides were identified from whey protein hydrolysates(WPH)in vitro in our previous study and the antihypertensive abilities of WPH in vivo were further investigated in the current study.Results indicated that WPH significantly inhibited the development of high blood pressure and tissue injuries caused by hypertension.WPH inhibited ACE activity(20.81%,P<0.01),and reduced renin concentration(P<0.05),thereby reducing systolic blood pressure(SBP)(12.63%,P<0.05)in spontaneously hypertensive rats.The increased Akkermansia,Bacteroides,and Lactobacillus abundance promoted high short chain fatty acid content in feces after WPH intervention.These changes jointly contributed to low blood pressure.The heart weight and cardiomyocyte injuries(hypertrophy and degeneration)were alleviated by WPH.The proteomic results revealed that 19 protein expressions in the heart mainly associated with the wingless/integrated(Wnt)signaling pathway and Apelin signaling pathway were altered after WPH supplementation.Notably,WPH alleviated serum oxidative stress,indicated by the decreased malondialdehyde content(P<0.01),enhanced total antioxidant capacity(P<0.01)and superoxide dismutase activity(P<0.01).The current study suggests that WPH exhibit promising antihypertensive abilities in vivo and could be a potential alternative for antihypertensive dietary supplements.

Yeast hydrolysate attenuates lipopolysaccharide-induced inflammatory responses and intestinal barrier damage in weaned piglets

Background Intestinal inflammation is the main risk factor causing intestinal barrier dysfunction and lipopolysaccharide(LPS)can trigger inflammatory responses in various eukaryotic species.Yeast hydrolysate(YH)possesses multibiological effects and is received remarkable attention as a functional ingredient for improving growth performance and promoting health in animals.However,there is still inconclusive on the protective effects of dietary YH supplementation on intestinal barrier of piglets.This study was conducted to investigate the attenuate effects of YH supplementation on inflammatory responses and intestinal barrier injury in piglets challenged with LPS.Methods Twenty-four piglets(with an average body weight of 7.42±0.34 kg)weaned at 21 days of age were randomly assigned to one of two dietary treatments(12 replications with one pig per pen):a basal diet or a basal diet containing YH(5 g/kg).On the 22nd d,6 piglets in each treatment were intraperitoneally injected with LPS at 150μg/kg BW,and the others were injected with the same amount of sterile normal saline.Four hours later,blood samples of each piglet were collected and then piglets were euthanized.Results Dietary YH supplementation increased average daily feed intake and average daily gain(P<0.01),decreased the ratio of feed intake to gain of piglets(P sponse,evidenced by the increase o=0.048).Lipopolysaccharide(LPS)injection induced systemic inflammatory ref serum concentrations of haptoglobin(HP),adrenocorticotropic hormone(ACTH),cortisol,and interleukin-1β(IL-1β).Furthermore,LPS challenge resulted in inflammatory intestinal damage,by up-regulation of the protein or mRNA abundances of tumor necrosis factor-α(TNF-α),IL-1β,toll-like receptors 4(TLR4)and phosphor-nuclear factor-κB-p65(p-NFκB-p65)(P<0.01),and down-regulation of the jejunal villus height,the protein and mRNA abundances of zonula occludens-1(ZO-1)and occludin(OCC;P<0.05)in jejunal mucosa.Dietary YH supplementation decreased the impaired effects of ACTH,cortisol,HP,IL-1βand diamine oxidase in serum(P<0.05).Moreover,YH supplementation also up-regulated the jejunal villus height,protein and mRNA abundances of ZO-1 and OCC(P<0.05),down-regulated the mRNA expressions of TNF-αand IL-1βand the protein abundances of TNF-α,IL-1β,TLR4 and p-NFκB-p65 in jejunal mucosa in LPS-challenged pigs(P<0.01).Conclusion Yeast hydrolysate could attenuate inflammatory response and intestinal barrier injury in weaned piglets challenged with LPS,which was associated with the inhibition of TLR4/NF-κB signaling pathway activation.

Supplementation with yak (Bos grunniens) bone collagen hydrolysate altered the structure of gut microbiota and elevated short-chain fatty acid production in mice

In this study, yak bone collagen hydrolysate(YBCH)was produced by mixed proteases and provided to standard-diet mice at a different dose(low dose(LD), medium dose(MD), and high dose(HD))to investigate its effects on the composition of gut microbiota and short-chain fatty acids(SCFA)production. It was found that YBCH was mainly composed of small molecular peptides whose molecular weight below 2 000 Da. Notably, supplementation with different doses of YBCH could significantly downregulate the ratio of Firmicutes to Bacteroidetes in the fecal microbiota. At the family level, the Lachnospiraceae abundance was significantly reduced in the YBCH gavage groups(mean reduction ratio 41.7 %, 35.2%, and 36.4% for LD, MD, and HD group, respectively). The predicted functions of gut microbes in the MD group were significantly increased at “lipid metabolism” and “glycan biosynthesis and metabolism”. Moreover, the SCFA production in the YBCH groups was elevated. Especially, the concentration of acetic acid, propionic acid, and butyric acid in the MD group was separately increased 79.7%, 89.2%, and 78.8% than that in the NC group. These results indicated that YBCH might be applied in the development of functional food for intestinal microecological regulation.

Hydrolysable Chestnut Tannin Extract Chemical Complexity in Its Reactions for Non-Isocyanate Polyurethanes(NIPU)Foams

Non-isocyanate polyurethane(NIPU)foams from a commercial hydrolysable tannin extract,chestnut wood tannin extract,have been prepared to determine what chemical species and products are taking part in the reactions involved.This method is based on two main steps:the reaction with dimethyl carbonate and the formation of urethane bonds by further reaction of the carbonated tannin with a diamine-like hexamethylene diamine.The hydroxyl groups on the tannin polyphenols and on the carbohydrates intimately linked with it and part of a hydrolysable tannin are the groups involved in these reactions.The carbohydrate skeleton of the hydrolysable tannin is also able to participate through its hydroxyl groups to the same two reactions rendering the whole molecular complex able to react to form NIPUs.The analysis by Matrix-Assisted Laser Desorption Ionization(MALDI-TOF)mass spectrometry and 13C Nuclear Magnetic Resonance(13C NMR)to further investigate the reaction mechanisms involved revealed the unsuspected complexity of chestnut hydrolysable tannin,with different fragments reacting in different manners forming a hardened network of considerable complexity.As the morphology and performance of these types of foams changes slightly with the change in the amount of glutaraldehyde and hexamine hardeners,the best performing foam formulation previously determined was scanned by SEM and analysed chemically for the structures formed.

响应面法优化长柄扁桃肽的酶解制备工艺

为高值化开发长柄扁桃种仁蛋白,以长柄扁桃种仁为原料,脱脂后提取水溶性蛋白,采用蛋白酶对其酶解制备长柄扁桃肽。通过比较5种蛋白酶对长柄扁桃水溶性蛋白水解度及酶解产物抗氧化活性的影响,优选合适的酶解用酶,在此基础上,采用单因素实验和响应面实验优化了长柄扁桃多肽的制备工艺。结果表明:采用碱性蛋白酶酶解可以得到更高的长柄扁桃蛋白水解度(16.03%)和酶解产物DPPH自由基清除率(59.49%),更适于长柄扁桃蛋白的酶解;长柄扁桃蛋白的最优酶解工艺条件为酶解温度57℃、酶解时间4 h、碱性蛋白酶用量1 192 U/g、pH 8.4,在此条件下长柄扁桃蛋白水解度为18.12%。酶解长柄扁桃蛋白制备多肽可提高长柄扁桃种仁的附加值,同时可为功能性肽产品提供优质原料。

基于体外仿生酶水解物能值和化学成分预测谷物饲料原料的鸡代谢能值

【目的】利用单胃仿生消化系统测定小麦、稻谷及糙米原料的鸡酶水解物能值(EHGE),结合两种体内法(自由采食法(FF)和排空强饲法(TF))测定的小麦、稻谷及糙米原料的鸡代谢能值,建立基于酶水解物能值和原料化学成分的鸡代谢能值预测模型,为谷物原料鸡代谢能值快速预测提供参考。【方法】使用单胃仿生消化系统分别测定3种来源的小麦、稻谷及糙米共计9个样品的鸡酶水解物能值(EHGE),每个谷物样品设置5个重复,每个重复1根消化管。结合前期通过自由采食法和排空强饲法测定的同批次原料的鸡表观代谢能值(AME)和真代谢能值(TME),利用线性回归建立基于化学成分及酶水解物能值的AME、TME预测模型。【结果】(1)在干物质基础下,3种来源的小麦原料酶水解物能值分别为14.46、14.63和14.80 MJ·kg^(-1);3种来源的稻谷原料酶水解物能值分别为12.52、13.59和13.40 MJ·kg^(-1);3种来源的糙米原料酶水解物能值分别为14.74、15.10和15.23 MJ·kg^(-1)。(2)粗灰分和中性洗涤纤维分别与FF法测定的AME和TME(AME_(FF),TME_(FF))和TF法测定的AME和TME(AME_(TF),TME_(TF))呈极显著的负相关(P<0.01);EHGE与AME_(FF)、AME_(TF)、TME_(FF)、TME_(TF)均呈极显著正相关关系(P<0.01),相关系数分别为0.801、0.864、0.807和0.866。(3)相较于EHGE建立的代谢能预测模型,基于化学成分建立的预测模型有更高的决定系数(R2)、更低的残差标准差(RSD)。对于AME_(FF)和TME_(FF),Ash为最佳预测因子,预测模型为:AME_(FF)=16.728-0.842×Ash(R^(2)=0.809,RSD=0.826,P=0.001),TME_(FF)=16.812-0.842×Ash(R^(2)=0.816,RSD=0.806,P=0.001);对于AME_(TF)和TME_(TF),NDF为最佳预测因子,预测模型分别为:AME_(TF)=16.106-0.157×NDF(R^(2)=0.907,RSD=0.523,P<0.001),TME_(TF)=17.654-0.157×NDF(R^(2)=0.903,RSD=0.534,P<0.001)。【结论】小麦、和糙米的EHGE高于稻谷EHGE,且三类谷物原料的EHGE与体内法测定的代谢能值具有较好的相关性。本研究条件下,基于化学成分建立的谷物AME和TME预测模型优于基于EHGE建立的预测模型。

添加部分水解罗望子胶对酸木瓜果醋品质的影响

该研究以酸木瓜(Chaenomeles speciosa)为原料,通过部分水解罗望子胶(PHTG)对6株乳杆菌的增殖活性测定,选用鼠李糖乳杆菌(Lactobacillus rhamnosus)与酵母菌混菌进行酒精发酵,并从灵石醋醅中筛选鉴定出一株高产醋酸的巴氏醋杆菌巴士亚种(Acetobacter pasteuranus subsp. pasteuranus)LS-4用于醋酸发酵制备酸木瓜果醋。以未添加PHTG为对照,考察在酒精发酵阶段添加PHTG对酸木瓜果醋品质的影响。结果表明,添加1.0%PHTG,酒精发酵36 h后酒精度达3.3%vol,比对照组提高17.4%;醋酸发酵72 h后总酸含量达42.0 g/L,比对照组提高8.0%。香气成分分析表明,添加PHTG酸木瓜果醋共检出22种香气成分,其中醇类7种、酯类4种、酸类6种、醛酮类3种、酚类和烯烃类各1种,比对照新增了3种香气成分(正丁酸、2-戊酮和壬醛)。感官评价表明,添加PHTG有效提升酸木瓜果醋的口感和气味评分,改善酸木瓜果醋的感官品质。

乳酸菌协同发酵玉米蛋白水解物工艺条件优化及其对抗氧化活性影响

该文以玉米蛋白水解物为原料,以鼠李糖乳杆菌YY⁃15和发酵乳杆菌YY⁃16为发酵菌株,通过单因素试验和响应面试验优化发酵条件,并对发酵后玉米蛋白水解物的体外抗氧化能力和氨基酸含量进行分析评价。结果表明,两株乳杆菌协同发酵玉米蛋白水解物的最佳发酵工艺为菌种体积比3∶1,玉米蛋白水解物浓度20.50%,接种量4%,果葡糖浆添加量5%,发酵温度39.5℃,发酵时间24 h。在该条件下,发酵后玉米蛋白水解物的体外DPPH自由基、羟自由基和超氧阴离子自由基三者清除能力的IC50值分别为0.227、0.200、12.851 mg/mL,Fe^(2+)螯合能力的IC_(50)为1.856 mg/mL,与发酵前相比分别提高了50.65%、34.64%、6.41%、41.36%。

玉米蛋白水解物对幽门螺旋杆菌感染诱导小鼠胃损伤的拮抗作用

目的:研究玉米蛋白水解物对幽门螺旋杆菌感染诱导小鼠胃损伤的保护作用。方法:以健康的昆明雄性小鼠为研究对象,适应性喂养7 d后,随机分为正常组、模型组、CPN200组(200 mg/kg m_(b))、CPN400组(400 mg/kg m_(b))、CPN600组(600 mg/kg m_(b))和阳性对照组,通过灌胃幽门螺旋杆菌建立感染小鼠胃部模型,连续灌胃玉米蛋白水解物5周后,测定小鼠胃组织中抗氧化能力、炎症因子和核转录因子相关指标水平和小鼠胃组织形态学变化。结果:与模型组相比,玉米蛋白水解物干预可以显著提高机体抗氧化水平,超氧化物歧化酶、谷胱甘肽过氧化物酶水平显著提高(P<0.05),丙二醛水平显著降低(P<0.05)。小鼠胃组织中促炎因子和趋化因子肿瘤坏死因子-α、白细胞介素-1β、髓过氧化物酶、单核细胞趋化蛋白1、角质细胞趋化因子水平均显著降低(P<0.05)。与模型组相比,小鼠胃组织中核转录因子信号通路Toll样受体4、髓样分化因子88以及核转录因子κB(nuclear factor-κB,NF-κB)等关键代谢物水平均显著降低(P<0.05)。结论:玉米蛋白水解物可以显著升高机体抗氧化水平,减轻脂质过氧化程度,降低胃组织炎症反应和抑制NF-κB信号通路反应,从而起到对幽门螺旋杆菌感染诱导小鼠胃损伤的拮抗效果。

沙蚕运动饮料的制备及其对小鼠运动耐力的影响

以双齿围沙蚕小分子酶解产物(小于5 kDa)作为原料研制沙蚕运动饮料。通过考察不同辅料、不同含量的沙蚕小分子酶解产物、不同的灭菌方式对饮料DPPH自由基清除作用的影响并结合感官评价确定沙蚕运动饮料的最佳配方,并探究沙蚕运动饮料的抗疲劳功效。实验结果表明,沙蚕运动饮料的最佳配方为沙蚕小分子酶解产物(小于5 kDa)含量40%、白砂糖含量5%、罗汉果多糖含量0.02%、柠檬汁含量1.2%、磷酸二氢钾含量0.05%、磷酸二氢钠含量0.1%、NaCl含量0.05%(均为质量分数),其(质量浓度为2.25 mg/mL)DPPH自由基的清除率为94.1%,IC_(50)值为0.8 mg/mL;动物实验结果显示,高剂量沙蚕运动饮料可显著(P<0.01)延长小鼠的负重游泳时间,低、中、高剂量沙蚕运动饮料均能显著增加小鼠肝糖原的含量(P<0.01)并能显著降低小鼠血清尿素氮含量(P<0.01),同时低剂量沙蚕运动饮料能显著降低小鼠血乳酸的含量(P<0.01),具有显著的抗疲劳功效。

脑蛋白水解物干预VaD小鼠海马神经元凋亡及可能的机制

目的本研究旨在探讨脑蛋白水解物-I(CH-I)干预血管性痴呆(VaD)小鼠海马神经元凋亡的作用及可能的机制。方法通过Y迷宫从70只雄性昆明小鼠中筛选出学习能力较好的小鼠60只,随机选择10只为假手术组,其余50只建立VaD小鼠模型,随机分为模型组,脑活素阳性药组,CH-I低、中、高剂量组[10、20、30 mg/(kg·d)体质量],连续给药4周。末次给药后,应用Y迷宫检测小鼠的学习记忆能力,采用HE染色观察小鼠海马区细胞的形态结构,TUNEL检测小鼠海马组织细胞凋亡,Western blot分析海马组织Akt、p-Akt、Bcl-2、Caspase-9(Casp-9)、Caspase-3(Casp-3)表达。结果脑蛋白水解物-I可改善VaD小鼠学习记忆能力,改善海马神经细胞的形态结构和凋亡,增强p-Akt、Bcl-2表达,同时抑制Casp-9和Casp-3表达。结论CH-I可能通过调节PI3K/Akt信号通路而抑制VaD小鼠海马神经细胞凋亡。

基于HS-GC-IMS和HS-SPME-GC-MS的蛋白酶对豆粕挥发性风味的影响分析

为研究不同蛋白酶酶解对豆粕挥发性风味成分的影响,选用4种蛋白酶(碱性蛋白酶、中性蛋白酶、木瓜蛋白酶、风味蛋白酶)对豆粕进行酶解,采用顶空-气相色谱-离子迁移谱(Headspace-gas chromatography-ion mobility spectroscopy,HS-GC-IMS)和顶空固相微萃取-气相色谱-质谱(Headspace solid phase microextraction-gas chromatography-mass spectrometry,HS-SPME-GC-MS)联用技术分析不同豆粕酶解物(Soybean meal hydrolysates,SMH)的挥发性风味成分,并结合主成分分析(Principal component analysis,PCA)、热图聚类和正交偏最小二乘判别法(Orthogonal partial least squares-discriminant analysis,OPLS-DA)对不同SMH进行分析。结果表明:碱性蛋白酶、中性蛋白酶、木瓜蛋白酶和风味蛋白酶酶解豆粕的挥发性风味成分存在较大差异。HS-GC-IMS鉴定出84种挥发性成分,筛选得到33种差异风味物质,发现酶解后酮类物质显著降低而醛类、醇类和酯类物质含量明显增加。PCA结果表明不同SMH之间的风味存在显著差异。最终通过OPLS-DA筛选出贡献较大的挥发性化合物,同时构建出可靠的用以鉴别SMH的模型。HS-SPME-GC-MS检测出103种差异风味物质,可用于区分不同SMH,被检出的挥发性组分中醛类、醇类和酮类等化合物为SMH风味的形成做出主要贡献,明晰了部分风味化合物形成的原因。PCA和聚类热图结果表明不同蛋白酶酶解对豆粕的挥发性风味物质的种类和含量有显著影响,其中,风味蛋白酶和木瓜蛋白酶对豆粕的风味改善最为显著。

大球盖菇酶解液中鲜味肽的分离鉴定及其协同增鲜效果分析

利用超滤、凝胶过滤色谱结合感官评价和电子舌分析技术,分离大球盖菇酶解液中鲜味肽组分,对鲜味最强组分F3中的鲜味肽进行反向高效液相色谱-串联质谱鉴定,并将鉴定得到的鲜味肽合成后进一步探讨其呈味特性。结果表明,大球盖菇酶解液F3组分中鉴定得到8条鲜味肽段,分别为ELWR、RLVDR、KPDNR、AHLRF、LDWDR、LAEWR、DDWWR和EGHKGW,它们均具有鲜味特征和鲜味增强作用,阈值分别为0.30~1.33mmol/L和0.53~2.43 mmol/L;除LDWDR外,7条多肽对味精溶液均有不同程度的鲜味提升,提升幅度0.18%~61.12%,ELWR、RLVDR、KPDNR、AHLRF和EGHKGW 5条多肽在低浓度时表现出良好的鲜味提升效果。RLVDR和KPDNR协同增鲜的鲜味峰值质量浓度为5mg/mL,LDWDR、LAEWR、DDWWR和EGHKGW在4mg/mL时达到鲜味峰值。鲜味肽的氨基酸组成和空间结构会影响其味觉属性。本研究结果为大球盖菇鲜味肽的开发利用提供了理论依据。

兰茂牛肝菌酶解产物调味油美拉德反应增香工艺优化及电子鼻分析

本文以兰茂牛肝菌酶解产物冻干粉为主要原料,通过优化美拉德增香反应条件,得到了兰茂牛肝菌调味油的最佳制备工艺。以电子鼻传感器响应值及感官评价得分为评价指标,通过单因素实验和正交试验优化了兰茂牛肝菌调味油的制备工艺参数。结果表明:最佳制备工艺为:兰茂牛肝菌酶解产物冻干粉与玉米油混合比例为1:40(w/w),葡萄糖添加量为5%、L-谷氨酸添加量为3%、美拉德反应时间40 min、反应温度140℃。在该条件下制备的兰茂牛肝菌调味油香气浓郁、协调,具有兰茂牛肝菌特有风味,经电子鼻分析香气组分发现硫化物、氮氧化物、醛类、醇酮类为主要香气组分。经品质检测,该调味油各项理化指标均符合国家标准,且含有能量3693 kJ/100 g、脂肪99.8 g/100 g。

酵母水解物对克氏原螯虾生长性能、消化、抗氧化和免疫能力的影响

实验研究了添加不同水平酵母水解物(Yeast hydrolysate,YHY)对克氏原螯虾(Procambarus clarkii)生长性能、消化、抗氧化和非特异性免疫能力的影响。实验选用300尾平均体重为(6.43±0.55)g的个体,随机分为5组,分别饲喂在基础饲料中添加0(对照组)、0.5%、1%、2%和4%YHY的饲料,每组3个重复,养殖密度为20尾/缸。为期8周的实验结束后,测定克氏原螯虾生长指标、胃和肝胰腺消化酶活性、肝胰腺抗氧化性能、血清生化指标和免疫酶活性。结果表明:(1)饲料中添加1%—4%YHY对该虾生长指标有促进作用。其中,2%添加组的存活率(SR)、最终体重(FBW)、最终体长(FBL)和肝胰腺指数(HSI)达最大值且显著高于对照组(P<0.05),增重率(WGR)和特定生长率(SGR)在1%添加组达到最大值且显著高于其余各组(P<0.05);(2)1%YHY添加组的全虾粗蛋白质含量显著高于其他组(P<0.05),而肌肉粗蛋白和粗脂肪含量在2%添加组达到最大值;(3)与对照组相比,2%—4%YHY添加组的胃和肝胰脏消化酶活性显著提高(P<0.05);(4)2%YHY添加组的肝胰腺抗氧化酶(过氧化氢酶,CAT;总超氧化物歧化酶,T-SOD;总抗氧化能力,T-AOC)和免疫酶(碱性磷酸酶,AKP;酸性磷酸酶,ACP)的活性达到最大值、丙二醛(MDA)的含量达到最小值,且与对照组相比均有显著差异(P<0.05);(5)2%YHY添加组该虾血清中总蛋白(TP)和白蛋白(ALB)含量显著高于其他组(P<0.05),1%和2%YHY添加组谷丙转氨酶(ALT)和谷草转氨酶(AST)活性显著低于其他各组(P<0.05)。结果表明,饲料中添加2%的酵母水解物可显著提高克氏原螯虾的消化、生长及肌肉粗蛋白和粗脂肪含量,并显著改善其抗氧化和非特异性免疫能力。

大米蛋白酶解物—黄原胶纳米载体的制备及性质研究

目的:提高疏水性生物活性物质的水溶性和稳定性。方法:利用大米蛋白酶解物(RPH)和黄原胶(XG),以疏水性模型活性物质姜黄素(Cur)为输送对象,构建了RPH-XG-Cur纳米输送体系,测定并分析纳米粒子的包封效果、稳定性、抗氧化性以及形成机制。结果:RPH-XG-Cur纳米粒子的姜黄素包封率为78.40%,粒径74.78 nm,多分散指数0.36,Zeta电位-27.93 mV,添加黄原胶可显著提高纳米粒子的包封性能以及pH和离子强度稳定性;傅里叶红外光谱和荧光光谱分析表明氢键、静电相互作用和疏水相互作用均参与纳米粒子的形成。结论:RPH-XG纳米体系具有作为疏水性生物活性物质纳米输送载体的应用潜力。

海藻酶解物对大黄鱼生长和肠道菌群结构的影响

为明确海藻酶解物饲喂大黄鱼的应用效果及对肠道菌群的影响,2022年11—12月在福建宁德海域使用添加0.5%复合海藻酶解物和0.5%海带酶解物的自配饲料饲养网箱养殖的大黄鱼8周,测定大黄鱼的存活率和平均增重,并采用NovaSeq PE250方案对肠道内容物进行16S rDNA扩增子测序,分析肠道菌群组成和特定菌群的相对丰度。结果显示:0.5%的复合海藻酶解物或0.5%的海带酶解物均可显著提高大黄鱼的存活率和平均增重(P<0.05);肠道菌群分析显示0.5%复合海藻酶解物组大黄鱼肠道中扩增子序列变体(ASVs)达1353种,以厚壁菌门(Firmicutes)、变形菌门(Proteobacteria)、拟杆菌门(Bacteroidota)、梭杆菌门(Fusobacteriota)和放线菌门(Actinobacteriota)为主,而0.5%海带酶解物组大黄鱼肠道中ASVs仅242种,各样本中以厚壁菌门和脱硫杆菌门(Desulfobacterota)为主,变形菌门相对丰度较低,均与对照组(749个ASVs,各样本中菌门相对丰度无规律)有较大差异;基于KEGG的肠道菌群功能分析显示在淀粉和蔗糖代谢、谷胱甘肽代谢、磷酸转移酶系统、氰基氨基酸代谢、亨廷顿病和其他糖降解上3组存在显著差异(P<0.05);进一步分析发现,0.5%复合海藻酶解物增加了大黄鱼肠道菌群α多样性并提高了拟杆菌属及丁酸合成相关细菌的相对丰度,而0.5%海带酶解物则降低了大黄鱼肠道菌群α多样性,但可抑制肠道中假单胞菌属细菌的生长,且体外培养试验证实褐藻寡糖可极显著抑制变形假单胞菌生长(P<0.01)。综上可知,本试验制备的2种海藻酶解物可调节大黄鱼形成不同的肠道菌群结构,并均可促进大黄鱼的健康和生长,该结果可为大黄鱼海藻类饲料添加剂的开发和通过调整大黄鱼肠道菌群改善大黄鱼健康和生长的饲料添加剂研发提供数据参考。