Effects of Dietary Yeast Cell Wall Polysaccharides Supplementation to Late Gestation and Lactation Diets on Reproductive Performance and Blood Profiles of Sows and Their Offspring

This study was conducted to determine the effects of yeast cell wall polysaccharides（YCWP） on reproductive performance, serum profiles and milk composition during late gestation and lactation. A total of 96 sows（Landrace × Yorkshire） were blocked on a basis of breed, parity（2-3）and their respective d 85 of gestation, and then randomly allotted to the following three dietary treatments： CON（basal diet, treatment 1）, YCWP1（CON＋0.2% YCWP, treatment 2） and YCWP2（CON＋0.4% YCWP, treatment 3）. The experiment lasted from d 85 of gestation to weaning（d 21 of lactation）. Sows fed YCWP diets had lower backfat thickness reduction from postpartum to weaning（ P〈0.05）. The supplementation of YCWP tended to increase litter weight at weaning（P=0.08） compared with CON. The non-lipid and total milk solids in colostrum was improved by YCWP2（P〈0.05）.No differences were observed in milk composition among dietary treatments（ P〉0.05）. The supplementation of YCWP decreased（P〈0.05） the levels of alanine amino transferase（ALT）, aspartate amino transferase（AST）, while it did not affect（ P〉0.05） alkaline phosphatase（ALP）, total protein（TP）,albumin（ALB）, globulin（GLB）, glucose（GLU）, total cholesterol（TC）, triglyceride（TG） or immunoglobulin G（IgG） in the sow serum. The serum IgG of piglets was increased by the YCWP. The levels of serum ALT and AST were reduced（P〈0.05） for suckling piglets in YCWP treatments. Taken together, the results of current studies might indicate beneficial effects of YCWP supplementation to late gestation and lactation diets on the sow productivity by improving litter weight at weaning, reducing backfat loss, and increasing serum IgG concentrations of piglets.

Determination of <i>α</i>-1,3-Linked Mannose Residue in the Cell Wall Mannan of <i>Candida tropicalis</i>NBRC 1400 Strain

To investigate the chemical structure of cell wall mannan obtained from pathogenic yeast, Candida tropicalis NBRC 1400 (former antigenic standard strain, IFO 1400). As a result of two-dimensional NMR analysis, it was shown that the mannan of this strain is composed of α-1,6-, α-1,3-, α-1,2- and β-1,2-linked mannose residues. In this research, the mannan was subjected to three degradation procedures, acid-treatment, α-mannosidase, and acetolysis under two conditions in order to determine the chemical structure of the antigenic oligomannosyl side chains in this molecule. The 1H-nuclear magnetic resonance spectra of resultant oligosaccharides, pentaose and hexaose, demonstrated the existence of the oligomannosyl side chains corresponding to Manα1-3Manα1-2Manα1-2Manα1-2Man and Manα1-3Manα1-2Manα1-2Manα1-2Manα1-2Man, respectively, which have previously also been found in Candida albicans serotype A strain mannans. These findings indicate that C. tropicalis and C. albicans serotype A have no significant difference in the chemical structure of these cell wall mannans. Therefore, it can be interpreted that it is extremely difficult to distinguish both species by targeting the antigenic group in these mannans.

酵母细胞壁来源、作用机理及在动物养殖中的应用

酵母细胞壁具有吸附病原微生物、调整有益菌落和调节免疫功能等作用,其作为酵母类生物饲料原料的重要组成部分,已经被广泛应用于畜禽养殖的各个环节。本文就酵母细胞壁来源、组成、作用机理及在动物养殖中的应用进行综述,以期为酵母细胞壁在实际生产中的合理应用提供理论参考。

Optimization of Fermentation Condition of Yeast Culture

Culture condition of every phase for fermentation of yeast culture was studied, and its solid and liquid conditions of elaboration were optimized to improve the total counts of living cells. Results showed that microzyme grew best at 30℃ when solid fermented, and the count of the living cells reached the tiptop with pH 5.5. The count of Candida tropicalis could reach 137.96× 10^9 cfu·g^-1, the count of Saccharomyces cerevisia could reach 134.62× 10^9 cfu·g^-1 the best liquid fermentation condition for cell-wall broken was 50℃ for 28 h, the rate of cell-wall broken could reach 80% at least; the rate of vitamin loss in yeast could be the minimun, the loss rate of vitamin B6 in Candida tropicalis and Saccharomyces cerevisiae was 8.71% and 19.54% respectively, the loss rate of vitamin B2 was 19.39% and 13.18%, respectively, and the loss rate of vitamin B6 was 6.3% and 3.04%, respectively.

酵母细胞壁对白羽肉鸡肠道发育的影响

为了探明酵母细胞壁(YCW)对肉鸡小肠各段肠道组织形态、肠道内容物PH值和肠道微生物的影响,选用1日龄科宝肉鸡200只,随机分为4个组,每组5个重复,每个重复10只鸡。对照组A饲喂基础日粮,试验组B、C和D在基础日粮中分别添加250、500 g/t和1000 g/t YCW,试验期42 d,在21日龄和42日龄测量了小肠各段长度和重量,在42日龄采集了各段肠道食糜检测pH值和HE染色,将42日龄采集的盲肠食糜采用16S高通量检测微生物多样性。结果表明:(1)在21日龄时:与对照组相比,添加500 g/t YCW组的空肠长度显著提高(P<0.05);添加500 g/t YCW组十二指肠和空肠的相对长度显著提高(P<0.05);添加1000 g/t YCW组十二指肠重量和相对重量显著提高(P<0.05)。(2)42日龄各组间的小肠各段肠绒毛高度和肠隐窝深度的差异不显著(P>0.05)。(3)与对照组相比,试验组肠道食糜pH都有所下降,各组间差异不显著(P>0.05)。(4)肉鸡盲肠微生物群落ASV、等级丰度曲线和稀释曲线分析表明,随着YCW添加量的加大,盲肠ASV/OTU总数目和独有数目会减少。Alpha多样性分析表明,添加250 g/t YCW组的微生物菌落多样性和菌落丰富度表现最佳,各组间无显著差异(P>0.05)。肉鸡盲肠微生物LEfSe分析基于分类等级树的组间差异分类单元展示,o_Lactobacillales、g_Enterococcus、f_Enterococcaceae、g__cc_115在各组中差异表达,o_Lactobacillales、g_Enterococcus、f_Enterococcaceae在A组中的丰度最高,g__cc_11在C组中的丰度最高。以上结果表明,YCW的添加可改善和维持肠道酸性环境,促进肉鸡养殖前期肠道发育,调控肠道微生物丰度,促进肠道健康,提高养殖生产效益。

酵母细胞壁多糖对柔嫩艾美耳球虫感染雏鸡血清抗氧化能力的影响

【目的】旨在评价酵母细胞壁多糖对柔嫩艾美耳球虫感染雏鸡血清抗氧化能力的影响。【方法】选取1日龄健康雏鸡180只,随机分为阴性对照组(雏鸡基础日粮+不攻虫)、阳性对照组(雏鸡基础日粮+攻虫)、酵母细胞壁多糖低剂量组(雏鸡基础日粮+酵母细胞壁多糖500mg/kg+攻虫)、酵母细胞壁多糖中剂量组(雏鸡基础日粮+酵母细胞壁多糖750mg/kg+攻虫)和酵母细胞壁多糖高剂量组(雏鸡基础日粮+酵母细胞壁多糖1 000mg/kg+攻虫)。14日龄时,除阴性对照组外其余各组雏鸡经口感染5 000个柔嫩艾美耳球虫孢子化卵囊。分别于21日龄和28日龄时,心脏采血后分离血清,采用酶联免疫吸附法检测过氧化氢酶活性、总超氧化物歧化酶活性、谷胱甘肽过氧化物酶活性和丙二醛的含量。于28日龄时摘取各组盲肠并石蜡包埋,切片后HE染色,在显微镜下观察盲肠的病理变化。【结果】与阳性对照组相比,酵母细胞壁多糖可以缓解柔嫩艾美耳球虫引起的盲肠病变,还可以显著提高同日龄柔嫩艾美耳球虫感染雏鸡血清中的谷胱甘肽过氧化物酶活性、过氧化氢酶活性和超氧化物歧化酶活性(P<0.05)且呈现一定正相关;显著降低其血清中丙二醛含量(P<0.05),且呈现一定负相关。【结论】酵母细胞壁多糖可通过提高感染柔嫩艾美耳球虫雏鸡的抗氧化能力而减轻柔嫩艾美耳球虫对雏鸡肠道损伤,以基础日粮中1 000mg/kg酵母细胞壁多糖为最适添加剂量。

酵母细胞壁多糖对鸡柔嫩艾美耳球虫病的预防效果

【目的】为探究酵母细胞壁多糖对鸡柔嫩艾美耳球虫病的预防效果。【方法】180只1日龄雏鸡常规饲养至12日龄,随机分为5组,阴性对照组(不攻虫)、阳性对照组(攻虫)、酵母细胞壁多糖低剂量组(酵母细胞壁多糖500 mg/kg+攻虫)、酵母细胞壁多糖中剂量组(酵母细胞壁多糖750 mg/kg+攻虫)、酵母细胞壁多糖高剂量组(酵母细胞壁多糖1000 mg/kg+攻虫)。14日龄时,除阴性对照组外其余4组雏鸡分别经口感染5000个柔嫩艾美耳球虫孢子化卵囊。于21日龄和28日龄,采血分离血清测定IgG抗体和相关细胞因子,并同时测定所有鸡只的抗球虫指标。【结果】日粮中添加酵母细胞壁多糖能促进鸡的生长,降低感染鸡的盲肠病变值和卵囊值,提高抗球虫指数(ACI),其中高剂量组ACI为169.3,表现出较好的抗球虫效果。同时,日粮中添加酵母细胞壁多糖能促进雏鸡免疫器官的发育,提高其血清中细胞因子IFN-γ、IL-2以及抗体IgG的水平。【结论】酵母细胞壁多糖对雏鸡感染柔嫩艾美尔球虫有一定的预防作用。

Impacts of low level aflatoxin in feed and the use of modified yeast cell wall extract on growth and health of nursery pigs

This study was to investigate the effect of corn naturally contaminated with aflatoxins(AF)under the regulatory level on the growth performance and health of nursery pigs,and the efficiency of yeast cell wall based feed additive(YC)mainly composed ofβ-glucans and mannan oligosaccharide(MOS)(Integral A+,Alltech,Lexington,KY)in prevention of mycotoxicosis.Pigs(60 barrows and 60 gilts at 6.02 ± 0.83kg BW)were randomly allotted to 4 treatments in a randomized complete block design based on a 2×2 factorial arrangement with 10 pens(5 barrow and 5 gilt pens)per treatment and 3 pigs per pen.Pigs were fed experimental diets for 5 wk.First factor was AF(0 or 20 mg/kg in feed)and the second factor was YC(0 or 2 g/kg in feed).Feed intake and body weight were measured weekly,and blood samples were used to measure blood cell counts,immunoglobulin G(Ig G),tumor necrosis factor-a(TNF-a),oxidative damage status,and serological evaluation related to liver health.Aflatoxin decreased(P<0.05)the number of platelet count(247.4 to 193.5×10~3/μL),and it also tended to increase the level of albumin(P=0.055,3.46 to 3.63 g/d L),albumin:globulin ratio(P=0.050,2.09 to 2.37),and Ca(P=0.080,10.79 to 10.97 mg/d L).Yeast cell wall based feed additive increased(P < 0.05)ADG(493 to 524 g/d),and ADFI(796 to 846 g/d)of pigs whereas G:F was not affected,and it also tended to increase(P=0.055)albumin level(3.46 to 3.63 g/d L).Interactions(P < 0.05)on hemoglobin,hematocrit,and platelet count indicated that YC further increased their levels when pigs were eating AF contaminated feed.Interactions(P < 0.05)on urea nitrogen and blood urea N to creatinine ratio indicated that YC further decreased their levels when feed were contaminated with AF.In conclusion,low level of 20 mg AF/kg under the regulatory level had minor effects on hematology without affecting growth performance,however the supplementation of 2 g/kg YC as a source ofβ-glucans and MOS in feed can improve feed intake and therefore the growth of pigs.

Effects of yeast cell wall on growth performance, immune responses and intestinal short chain fatty acid concentrations of broilers in an experimental necrotic enteritis model

Subclinical necrotic enteritis(NE) causes devastating economic losses in the broiler chicken industry,especially in birds raised free of in-feed antibiotics. Prebiotics are potential alternatives to in-feed antibiotics. Yeast cell wall extract(YCW) derived from Saccharomyces cerevisiae is a prebiotic with known immune modulating effects. This study examined the effects of YCW and antibiotics(AB) during subclinical NE on broiler growth performance, intestinal lesions, humoral immune response and gut microflora metabolites. The study employed a 2 × 3 factorial arrangement of treatments. Factors were:NE challenge(yes or no) and feed additive(control, AB, or YCW). Each treatment was replicated in 8 floor pens with 15 birds per pen. Challenged birds had higher feed conversion ratio(FCR) than unchallenged birds on d 35(P < 0.05). Dietary inclusion of AB decreased FCR regardless of challenge(P < 0.05) on d 24 and 35. Inclusion of YCW reduced serum interleukin-1(IL-1) concentration in NE challenged birds(P < 0.01) and increased immunoglobulin(Ig) G(P < 0.05) and Ig M(P < 0.05) levels compared to other dietary treatments regardless of challenge. Yeast cell wall extract increased formic acid concentration in cecal contents during challenge and increased butyric acid concentration in unchallenged birds on d 16.This study indicates YCW suppressed inflammatory response, promoted generation of immunoglobulin and increased short chain fatty acid production suggesting potential benefits to bird health.

Dietary supplementation of yeast cell wall improves the gastrointestinal development of weaned calves

The purpose of this study was to investigate the potential benefits of yeast cell wall(YCW)on the gastrointestinal development of weaned calves.Twenty healthy Holstein male calves(BW=92±8.29 kg and 60±5 d of age)were randomly allocated into 2 groups:CON with no YCW,and YCW(accounted for0.16%of the basal diet).The dietary concentrate-to-roughage ratio was 40:60.All the calves were fed regularly twice a day at 09:00 and 16:00 and had free access to water.The experiment lasted for 60 d.The results showed that calves fed YCW showed higher(P<0.05)length,width,and surface area of papillae in the ventral sac of the rumen as compared to CON.For the dorsal sac of the rumen,the muscularis thickness was thicker(P<0.05)in the YCW group when compared with CON group.The villus height of YCW calves was higher(P<0.05)than that of CON in the ileum.Calves supplemented with YCW also showed a higher(P<0.05)villus height-to-crypt depth ratio in the ileum.The YCW calves exhibited a greater(P<0.05)thickness of the wall in the duodenum and jejunum.Calves supplemented with YCW improved(P<0.05)the claudin 1 mRNA expression in the ileum and occludin mRNA expression in the jejunum and ileum.The YCW increased(P<0.05)the contents of secretory immunoglobulin A in the jejunum and ileum of calves.In conclusion,dietary supplementation with YCW could improve the gastrointestinal development of weaned calves.

口服免疫多糖(酵母细胞壁)对南美白对虾抗哈维弧菌感染的作用

在南美白对虾(Penaeusvannamei)饲料中分别加100 0、200 0、300 0、400 0和500 0mg·kg-1Bm的免疫多糖(酵母细胞壁),连续投喂28d后,通过检测供试虾血清、肝胰腺和肌肉中酸性磷酸酶(ACP)、碱性磷酸酶(ALP)和过氧化物酶(POD)的活性及经过哈维弧菌的活菌攻毒,探讨口服不同剂量的免疫多糖(酵母细胞壁)对南美白对虾体内免疫相关酶活性的影响和对人工感染哈维弧菌抗病力的作用。结果表明,在南美白对虾饲料中添加100 0mg·kg-1Bm的免疫多糖(酵母细胞壁),能显著提高供试南美白对虾血清和肌肉中ACP和ALP活性(t测验,P<0 05),极显著地提高肝胰腺中ACP、ALP和POD的活性(t测验,P<0 01),增强抗哈维弧菌感染的能力。免疫多糖(酵母细胞壁)不同添加剂量的试验组之间则未出现显著差别(t测验,P>0 05)。试验结果表明免疫多糖(酵母细胞壁)在南美白对虾饲料中的添加量以100 0mg·kg-1Bm为宜。

免疫多糖(酵母细胞壁)对中华鳖非特异性免疫功能的影响

报道了口服免疫多糖（酵母细胞壁）对中华鳖（Pelodiscus sinensis）非特异性免疫功能影响的研究结果。试验中共设6个组，在各组饵料中免疫多糖的添加量依次为每千克鳖重0mg（对照组）、500．0mg（试验Ⅰ组）、1000．0mg（试验Ⅱ组）、1500．0mg（试验Ⅲ组）、2000．0mg（试验Ⅳ组）和2500．0mg（试验Ⅴ组）。投喂28d后，取其血液，测定了中华鳖血液中自细胞的吞噬活性、血清溶菌活力和补体活性。研究结果表明，试验Ⅰ～Ⅲ组中华鳖白细胞吞噬活性和溶菌酶的活性均显著高于对照组（t测验，P％0．05），而试验Ⅳ组和Ⅴ组与对照组中华鳖血液中自细胞的吞噬活性和溶菌酶活性没有显著差异（t测验，P〉0．05），补体C3和C4活性最高的是投喂量为每千克鳖重1000．0mg和1500．0mg的第Ⅱ组与第Ⅲ组，2个组与对照组间存在显著差异（t测验，P〈0．05），而第1组、第Ⅳ组和第Ⅴ组与对照组之间无显著性差异（t测验，P〉0．05）。研究结果证明在中华鳖饵料中添加免疫多糖（酵母细胞壁）的量以每千克鳖重1000．0nag左右为宜，超过1500．0mg对中华鳖的免疫刺激作用会逐渐降低。

免疫多糖对南美白对虾免疫相关酶的激活作用

将免疫多糖 (酵母细胞壁 )作为免疫激活剂注射到南美白对虾 (Penaeusvannawei)体内后 ,通过定时测定供试虾血清、肌肉和肝胰腺提取液中的酸性磷酸酶 (ACP)、碱性磷酸酶 (ALP)和过氧化物酶 (POD)的活性 ,探讨了免疫多糖 (酵母细胞壁 )对南美白对虾免疫系统的免疫刺激效果。结果表明 ,南美白对虾经注射免疫多糖(酵母细胞壁 )刺激后 ,肝胰腺中的ACP和ALP活性明显增加 ,在注射后 72h ,ACP活性由对照组的 31.3U/L提高到 93.4U/L ,ALP活性由 38.3U/L提高到 12 8.0U/L ,而在血清和肌肉中ACP和ALP的活性没有明显变化。与对照组虾相比 ,试验组虾的血清、肌肉和肝胰腺提取液中POD活性均没有明显变化。

不同破壁方法提取酵母菌总RNA的比较

选择液氮碾磨、反复冻融、超声波、加玻璃珠漩涡振荡和蜗牛酶酶解5种方法破碎酵母菌细胞壁,再使用Trizol法提取酵母菌总RNA,通过对总RNA进行质量浓度和纯度分析,比较不同破壁方法对酵母菌总RNA提取的影响。结果表明:在使用Trizol法提取酵母菌总RNA的实验中,反复冻融和液氮碾磨是较为有效且简便的酵母菌细胞壁破碎方法。

酵母细胞壁多糖的研究进展

随着科学技术的发展,多糖的活性功能已经被人们所认识。而酵母细胞壁多糖作为多糖中的一种,其研究也在不断深入。酵母细胞壁多糖具有许多活性功能,如能吸附病原菌,增强细胞免疫力,提高巨噬细胞活性,抗辐射,抗病毒,提高抗癌功能等。目前,酵母细胞壁多糖的提取方法主要是碱法、高压均质破壁法,酶法。在食品工业中,酵母细胞壁多糖能充当乳化剂、增稠剂、低热食品原料等角色。但由于提取技术的限制,其主要还是作为添加剂常见于饲料中。为了更好的利用酵母细胞壁多糖的功能价值,更充分的为人类健康服务,本文对酵母菌细胞壁多糖物质的活性功能,提取方法及其在食品中的应用进行了综述。

酵母细胞壁和益生素对蛋鸡生产性能及免疫功能的影响

本研究旨在探讨酵母细胞壁和益生素的不同添加剂量组合对蛋鸡生产性能与免疫功能的影响。试验选择19周龄体重相近、健康的海兰褐蛋鸡512只,随机分成4组,分别饲喂基础饲粮(对照组,A组)、基础饲粮+0.4 mg/kg酵母细胞壁+50 mL/t益生素(B组)、基础饲粮+0.8 mg/kg酵母细胞壁+100 mL/t益生素(C组)、基础饲粮+1.2 mg/kg酵母细胞壁+150 mL/t益生素(D组),预试期1周,正试期8周。结果表明:1)整个试验期各组间蛋鸡日采食量、平均蛋重没有显著差异(P>0.05)。B、C和D组蛋鸡日产蛋量与产蛋率比A组均有不同程度的提高,其分别提高了2.76%(P>0.05)、6.22%(P<0.05)、2.26%(P>0.05)和2.83%(P>0.05)、6.19%(P<0.05)、2.27%(P>0.05);料蛋比降低,分别下降了3.83%(P<0.05)、6.70%(P<0.05)、2.87%(P>0.05)。C组蛋鸡日产蛋量、产蛋率与B、D组相比均有显著提高(P<0.05);料蛋比下降,分别下降了2.99%(P>0.05)和3.94%(P<0.05)。2)试验第14天和第28天,B、C和D组蛋鸡血清新城疫抗体效价均比A组有显著或极显著提高(P<0.05或P<0.01);C组蛋鸡血清新城疫抗体效价比B、D组均有提高,但差异不显著(P>0.05)。3)试验第14天和第28天,B、C和D组蛋鸡血液淋巴细胞转化率均比A组有显著或极显著提高(P<0.05或P<0.01);C组蛋鸡血液淋巴细胞转化率比B、D组均有提高,但差异不显著(P>0.05)。结果提示,饲粮中酵母细胞壁和益生素的不同添加剂量组合均可改善蛋鸡生产性能与免疫功能,以添加0.8 mg/kg酵母细胞壁+100 mL/t益生素效果最佳。

用酶法对啤酒酵母细胞破壁优化条件的研究

试验旨以溶菌酶、蜗牛酶对啤酒酵母进行破壁,从中筛选出最佳的破壁条件。以啤酒酵母作为破壁酵母细胞,采用四因素四水平的正交试验设计进行试验。结果表明,酶量10 mg.mL-1,pH 5.0,温度45℃,时间6 h时的破壁率均高于以上各因素的水平。各因素对破壁率的影响顺序为:温度>时间>酶量>pH。蜗牛酶和溶菌酶破壁率差异不显著(P>0.05)。结果揭示本试验条件下溶菌酶、蜗牛酶最佳破壁条件为酶量10 mg.mL-1,pH 5.0,温度45℃,时间6 h。

酵母细胞壁对犊牛生长性能、营养物质表观消化率和血清免疫指标的影响

本试验旨在研究饲粮添加酵母细胞壁(YCW)对犊牛生长性能、营养物质表观消化率和血清免疫指标的影响。选取体重[(112.57±8.29) kg]和日龄(60±5)相近、健康的30头荷斯坦断奶公犊牛,随机分为5个组,每组6个重复,每个重复1头牛。各组酵母细胞壁添加量分别占精料补充料的0(对照组)、0.20%、0.40%、0.80%和1.60%,饲粮精粗比为40∶60。试验期为60 d。结果表明:1)饲粮添加酵母细胞壁可提高犊牛平均日增重(ADG),0.20%和0.40%组ADG分别较对照组提高了10.64%和11.70%(P> 0.05); 0.40%组料重比较对照组降低了11.30%(P>0.05)。试验第60天,0.40%和0.80%组胸围指数和体躯指数显著高于对照组(P<0.05)。0.40%组犊牛粪便评分显著低于对照组(P<0.05)。2) 0.40%组中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)和钙表观消化率显著高于对照组(P<0.05),0.40%和0.80%组粗脂肪(EE)表观消化率显著低于对照组(P<0.05)。3)试验第30天,0.40%组血清免疫球蛋白G(IgG)含量显著高于对照组(P<0.05)。试验第60天,0.40%组血清免疫球蛋白A(IgA)含量显著高于对照组(P<0.05),1.60%组血清IgG含量显著高于对照组(P<0.05),0.80%组血清白细胞介素-4(IL-4)含量显著高于对照组(P<0.05),对照组血清肿瘤坏死因子-α(TNF-α)含量显著高于其他各组(P<0.05)。综上所述,饲粮添加酵母细胞壁可增强犊牛机体免疫力,降低犊牛腹泻,提高营养物质表观消化率,提高生长性能,其中添加0.40%酵母细胞壁的效果最好。

双螺杆挤压膨化破碎啤酒酵母细胞壁的研究

利用自行研制的双螺杆挤压膨化设备对啤酒酵母进行了挤压膨化破壁研究。通过单因素和正交优化试验,结果表明,在供料速度为4Hz、螺杆频率为35Hz、膨化温度130℃～140℃、加水量为10mL/min的情况下进行挤压膨化破壁,破壁率可达79.21%。所得的挤压样品与原料相比,可溶性蛋白含量增加了132%,酶解后可溶性蛋白质含量增加了156%,谷胱甘肽含量降低了14%,容重降低了55%。不仅大幅度提高了吸收利用率,还实现了对酵母的各种功效成分的提取。

酵母抽提物的生产技术进展

酵母抽提物作为重要的酵母衍生物之一,具有丰富的营养价值,凭借其自身优势广泛应用在食品加中,能显著增加食品的鲜味、风味。本文主要阐述了酵母抽提物的定义、生产现状和常用生产技术,着重对酵母细胞壁破壁技术、自溶促进剂技术、制备风味化酵母抽提物技术和提高酵母抽提物鲜味技术四种酵母抽提物生产新技术进行探讨。酵母抽提物生产新技术将会不断改进并得到越来越广泛的应用,在未来行业中占有举足轻重的地位。