Microbial Changes in Fermented Peanut and Soybean Pastes Containing Kojis Prepared using Aspergillus oryzae and Rhizopus oligosporus

Microbiological profiles of peanut and soybean misos containing 6 and 12% NaCl and kojis prepared with Aspergillus oryzae and Rhizopus oligosporus were monitored over a 90-day period of fermentation. Although total plate counts in misos containing R. oligosporus koji fluctuated while counts in misos containing A. oryzae koji remained constant during the fermentation period, the final microbial populations in sixteen test formulae were similar to the initial counts. Mold populations in mists containing two types of kojis declined similarly during fermentation. There was little difference in populations of Saccharomyces rouxii in misos containing the two types of mold kojis during the first month of fermentation; however, higher numbers of S. rouxii were noted in mitis containing R. oligosporus koji compared to those containing A. oryzae koji during later stages of fermentation. The final pH values of misos were similar, even though misos containing A. oryzae koji had a larger magnitude of drop in pH than did misos containing R. oligosporus koji over the 90-day test period.     

Fermentation of Corn Gluten Meal with Aspergillus oryzae and Rhizopus oligosporus

PER values determined for corn gluten meal (CGM) and CGM fermented with Aspergillus oryzae NRRL 1988 were not significantly different (P > 0.05) and both diets failed to meet maintenance requirements of rats. In order to characterize some of the changes that occur during fungal fermentation, CGM was also fermented for 4 days at 28°C with A. oryzae NRRL 1988 and NRRL 506 and Rhizopus oligosporus NRRL 2710 and NRRL 2549, respectively. Proteolytic activity, pH, and nitrogen content increased rapidly between 20 and 70 hr for all the fungi. Decreases in some amino acids were observed, possibly due to their catabolism by the molds. Lysine as a proportion of total essential amino acids released by pepsin and pancreatin in vitro was increased as a result of these fungal fermentations.     

Structural and Functional Properties of Fermented Soybean (Tempeh) by Using Rhizopus oligosporus

The effect of R. oligosporus on structural and functional properties of fermented soybean was studied. After 24 hours of fermentation, the amount of total free amino acids formed greatly increased in soybean (1.20 g/100 g soybean). The pH of the fermented soybean was neutral during the growth of the mold. The amount of g-amino butyric acid (GABA) gradually increased during fermentation of the soybean (21.4 mg/100 g soybean per 24 hours). The proteins (albumin, globulin, alkaline soluble) were rapidly degraded to amino acids and low-molecular-weight peptides. Instrumental texture of fermented soybean (48 hours) had higher weakness (7.14 N), modulus of elasticity (1.02 × 10⁹ Pa) and surrender value (8.17 × 10⁶ Pa); these values were significantly different (P < 0.05) compared with 24 and 72 hours fermentation. Cell structure of fermented soybean was proportionally disorganized during the course of fermentation. The cell walls, cytoplasm, and vacuoles could not be distinctly identified. R. oligosporus produced enzymes which hydrolyzed protein, lipid, and starch, providing growth substrates and playing a role in its metabolism. Metabolism of mold was attributed to soybean cell disorganization, and the ratio of mature mold became higher, which was indicated by dark color.     

Role of Carbohydrate-Cleaving Enzymes in Phenolic Antioxidant Mobilization from Whole Soybean Fermented with Rhizopus oligosporus

Previous research has suggested a relationship between free phenolic content and β-glucosidase activity in solid-state fermented food substrates and to amylase activity in germinating soybeans. This study was undertaken to examine the role of a number of carbohydrate-cleaving enzymes in phenolic antioxidant mobilization from whole soybean during solid-state fermentation. In addition to total soluble phenolic content, α- and β-glucosidase, α-amylase, and β-glucuronidase activities were measured in extracts of soybean fermented with a food-grade fungus, Rhizopus oligosporus. Antioxidant activity of the extracts was determined as 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging ability. Our results demonstrate that while total soluble phenolic content increased 120–135% in the extracts, increased antioxidant activity (+61%) was limited to the early fermentation period, with activity decreasing with increased culture time. Higher antioxidant activity was linked to increased glucosidase and glucuronidase activities, while high total phenolic content partly linked to increased amylase activity. The overall results (enzymatic activities and phenolic antioxidant contents) suggest the possible involvement of lignin remobilization and/or degradation activities, as well as phenolic detoxification activities, by Rhizopus oligosporus in phenolic antioxidant mobilization from fermented whole soybean.     

米根霉NCU1011发酵豆渣开发甜酱生产工艺研究

文章以米根霉Rhizopus oryzae NCU1011为发酵菌种,采用酱类固态发酵法生产豆渣甜酱。利用单因素优化试验及正交试验,研究豆渣初始水分含量、接种量、发酵时间对豆渣中还原糖、氨基酸态氮含量和感官品质的影响,确定米根霉发酵生产豆渣甜酱的最佳发酵工艺参数为:接种量2.75%、豆渣初始水分含量70%、发酵时间28 h,所得发酵豆渣甜酱中氨基酸态氮、还原糖和可溶性膳食纤维的含量分别提高到0.25%、5.05%、10.5%,口感细腻爽滑,发酵风味浓郁,其营养和食用价值提高,是一种营养丰富、口感风味俱佳的新型高纤维甜酱调味品。     

豆酱自然发酵过程中蛋白质和氨基酸的变化规律

为研究豆酱在自然发酵过程中蛋白质、氨基酸组成及含量的变化规律,以按照东北豆酱传统方法制作的自然发酵豆酱为研究对象,在检测蛋白质含量、氨基氮含量、氨基酸含量、非蛋白氮含量和水解指数等指标变化的基础上,对豆酱的氨基酸评分(amino acid score,AAS)、化学评分(chemical score,CS)、必需氨基酸指数(essential amino acid index,EAAI)进行分析。结果表明,豆酱蛋白质含量、非蛋白氮含量、蛋白水解指数先上升后下降;氨基氮含量则先不断增加后减少至稳定。自然发酵豆酱中共含有17种氨基酸,但不同发酵时期豆酱中氨基酸含量差异较大,成品豆酱中氨基酸总量维持在41.00 mg/g左右,明显高于生豆粉(11.42 mg/g)和熟豆粉(11.06 mg/g)中氨基酸总量。不同发酵时期豆酱中必需氨基酸与非必需氨基酸的比值在0.48~0.77之间,提示豆酱中的蛋白质为优质蛋白。分析不同发酵时期豆酱的AAS、CS和EAAI可知,发酵20 d时EAAI最高达29.41,发酵50~75 d豆酱的EAAI保持在16.16~17.40之间。通过比较4种呈味氨基酸的含量可知,甜味氨基酸苦味氨基酸鲜味氨基酸无味氨基酸。     

米曲霉发酵所制大豆肽的分离纯化与抗氧化性研究

利用辐照诱发米曲霉孢子突变,筛选得到酶活力强且特异性高的米曲霉诱变菌株。利用米曲霉诱变菌株对豆腐皮加工后的剩余豆浆(下浆水)进行发酵,制备大豆肽的发酵液,发酵液经超滤和凝胶过滤进行分离纯化,采用铁离子还原抗氧化剂能力测定法(FRAP法)和二苯基苦基苯肼法(DPPH法)研究不同相对分子质量大豆肽的抗氧化能力。结果表明,相对分子质量在1 000～10 000范围内的大豆肽具有很好的抗氧化活性,其中抗氧化性和稳定性最好的大豆肽组分的相对分子质量在1 200～1 400之间。     

传统豆酱和商品豆酱发酵过程中营养及理化指标动态

以山东传统豆酱和天源商品豆酱为研究对象,测定不同发酵阶段豆酱样品的营养及理化指标,探讨两种豆酱发酵过程中养分动态及成品豆酱的氨基酸含量差异,并分析两种豆酱的制作工艺。研究结果表明:山东豆酱的总酸在发酵过程中呈波动上升的趋势,成品酱总酸含量为6.26%;天源豆酱总酸呈逐步上升后趋于平稳的趋势,成品酱总酸含量为3.13%。山东豆酱与天源豆酱发酵过程中可溶性糖和有机碳含量呈下降的趋势,但天源豆酱的可溶性糖和有机碳含量显著高于山东传统豆酱。山东豆酱的有机碳和可溶性糖含量比商品豆酱下降快。两种豆酱的粗蛋白含量均呈先上升后下降的趋势,氨基酸态氮含量均呈逐渐上升趋势,山东豆酱的粗蛋白和氨基酸态氮含量明显高于天源豆酱。山东成品豆酱氨基酸总量为天源成品豆酱的1.3倍。除精氨酸和酪氨酸外,山东豆酱的各种氨基酸含量高于天源豆酱。     

纯种米曲霉发酵与自然发酵豆豉挥发性成分比较

采用气相色谱- 质谱的分析方法,对米曲霉纯种发酵制成的豆豉与传统自然发酵豆豉中挥发性成分变化进行比较分析。结果表明,共鉴定出包括酯类、吡嗪类、酮类、醇类、烷烃类、烯烃类、酸类、醛类、呋喃类、醛类等11 类51 个化合物。纯种发酵挥发性成分中含量较高的是酯类(58.53%)、酸类(23.98%)、烯烃类(10.07%)、酮类(5.56%),采用传统自然发酵制成产品中含量较高的是酸类(62.4%)、酯类(31.46%)、醛类(3.07%)、胺类(1.98%)。     

米曲霉优良菌株的筛选及在制曲发酵西瓜黄豆酱中的应用

为获得蛋白酶、淀粉酶活性优良的米曲霉菌株,采用牛津杯双层平板法初筛、制曲分析酶活性复筛的方法,从制酱用成品曲中获得1?株淀粉酶活性优良菌株CS3.04和1?株蛋白酶活性优良菌株CS3.22,结合形态特征,ITS?rRNA序列分析鉴定为米曲霉。将2?株米曲霉分别进行单一菌种制曲及混合菌种制曲发酵西瓜黄豆酱,与商业米曲霉菌株制曲发酵进行对比,结果显示：不同制曲方式发酵西瓜黄豆酱的理化指标变化趋势保持一致,混合菌种制曲发酵样品的还原糖及氨态氮含量最高,分别为107.37、6.76?g/kg,比接种商业米曲霉菌株制曲发酵的样品分别提高了11.02%、5.56%;采用液液萃取-气相色谱-质谱联用技术定性及定量分析西瓜黄豆酱的挥发性风味物质,发现混合菌种制曲发酵具有产醛类、醇类、酮类及短链酯类物质的优势,而接种CS3.04单一菌种制曲发酵更有利于产酸类及酚类物质;混合菌种制曲发酵样品整体感官评分优于单一菌种制曲发酵,且在香气与滋味上占有优势。混合菌种制曲发酵工艺因CS3.04和CS3.22的酶系互补作用,有效地提升了西瓜黄豆酱的品质。     

Solid-state fermentation of Lathyrus sativus seeds using Aspergillus oryzae and Rhizopus oligosporus sp T-3 to eliminate the neurotoxin β-ODAP without loss of nutritional value

The presence of a neurotoxic amino acid, 3-N-oxalyl-L-2,3-diaminopropanoic acid (β-ODAP), in the seeds of grass pea (Lathyrus sativus) is the cause of an irreversible spastic paraparesis, neurolathyrism, after over-consumption. This is a negative factor in an otherwise very tasty, nutritious, easily cultivated and hardy food crop in Asia and Africa. The reduction of β-ODAP to less than 10% of the original content has been reached by fermenting L sativas Jamalpur seeds with Aspergillus oryzae NRRL 1988 for 48 h, followed by fermentation with Rhizopus oligosporus sp T-3 for 48 h. Other nutritional qualities were also improved in the fermented seed meal: increased content of protein, higher amino acid scores for sulphur-containing and aromatic amino acids, better resistance to high temperature and to oxidation, and drastic reduction of the flatulence factors.     

Preparation and Properties of Rhizopus oryzae Lipase Immobilized Using an Adsorption-Crosslinking Method

The aim was to develop an enzyme immobilization method for Rhizopus oryzae lipase to improve its acidolysis activity and stability. Lipase was adsorbed into NKA-9 resin and then crosslinked with glutaraldehyde as a crosslinker. The optimum conditions obtained using the response surface methodology were as follows: 34.6 mg lipase/100 mg support, 4.1 h of adsorption time, 45°C, pH 6.8, 0.5% glutaraldehyde concentration, and 2.5 h of crosslinking time. The acidolysis activity of the immobilized lipase was 31.78%, the free lipase activity was only 11.02%. The immobilized lipase showed better performance, such as higher acidolysis activity, better pH tolerance and temperature stability, enhanced storage stability, and improved reusability.     

发酵豆制品酿造过程中组分和营养功能因子的变化及调控

发酵豆制品是发酵食品中的一大类,在亚洲国家人民饮食中占重要地位,并逐渐受到西方国家青睐。近年来,发酵豆制品酿造过程中产生的功能因子不断被报道,其抗氧化、降血压、降血糖、溶血栓、抗突变等功能性不断被揭示,引起世界广泛关注。发酵豆制品组分变化的调控对增强营养和富集功能因子意义重大,有利于进一步提升其食用价值,促进人类健康。本文综述发酵豆制品生产过程中与营养和功能相关的部分组分的变化及调控,并对该领域的科学问题进行展望。     

发酵麸皮混合物对面包品质的影响

为改善麸皮面包的品质,增加麸皮的利用率,本实验应用甜酒曲联合酵母发酵麸皮、黄豆和花生的混合物,得到发酵麸皮混合物。以面粉+发酵麸皮混合物总量为100 g(面粉90 g、发酵麸皮混合物10 g)计,制备发酵麸皮混合物面包(简称发酵麸皮面包),以普通面包、麸皮面包及添加黄豆、花生混合物的非麸皮添加物面包为对照,对这几种面包的品质、风味物质及抗氧化活性进行分析。结果表明:黄豆、花生的添加能够起到提升面包风味的作用;发酵麸皮混合物的添加可以改善麸皮面包的品质,其感官评分、弹性、硬度和色差L、b值极显著优于麸皮面包(P0.01),而与普通面包比较没有显著差异(P0.05);与3种对照面包样品比较,发酵麸皮面包的醇类、酯类和醛类等风味成分种类较多,且分布均匀,而且还检测出其特有的风味物质,分别为吡嗪类、呋喃类、乙基酯类;发酵麸皮面包的多酚、黄酮含量以及抗氧化活性指标也均最高。综上,发酵麸皮混合物能够改善麸皮面包的品质,并提高面包的抗氧化活性。     

Matching Changes in Sensory Evaluation with Physical and Chemical Parameters

Changes in pistachio nuts induced by roasting and salting processes, evaluated by both sensory and instrumental analyses are reported, looking for a match in both methods. Dried (DP), roasted (RP), and salted–roasted pistachios (SRP) were studied, including four groups of sensory attributes, six basic chemical parameters, complemented by volatile organic compounds (VOCs) and breaking force. Multivariate statistics helped with data interpretation, enabling correlations between two groups of variables. Key results show that the perception of roasting is associated with increased amounts of α-pinene and 3-carene in RP and SRP, while DP are associated with higher amounts of limonene, moisture, and bitterness. Sensory and puncture test measurements (texturometer) showed opposite results, which could be explained considering the loss of plasticity in RP and SRP. Current results present a novel approach for the evaluation of changes in the perception of pistachio quality by consumers, supported by both sensory and instrumental analyses using multivariate statistics for data evaluation.     

基于混合培养和高通量测序分析云南传统发酵豆豉中活性细菌群落

选择两个使用传统发酵的豆豉样品,先进行混合预培养,再对混合培养液进行DNA提取和16S rRNA基因扩增及焦磷酸测序,最后对得到的序列进行分析。结果表明：两个样品在序列相似度为98%时多样性均较高。其中XG_1的主要细菌为肠球菌、甲基营养型芽孢菌和乳酸片球菌,在XG_2中的主要细菌为枯草芽孢杆菌和甲基营养型芽孢杆菌。     

腐乳发酵过程中化学组分与质构的变化

研究腐乳发酵过程中化学组分含量和质构参数的变化。结果表明：在腐乳发酵过程中,蛋白质与脂肪含量逐步降低,pH 值先升高后降低,游离氨基酸态氮与游离脂肪酸含量逐步升高;腐乳低食盐含量下的化学组分含量均较高,且腐乳成熟时间较短。在腐乳发酵过程中,样品硬度先增大后减小,黏着性逐渐升高,弹性逐渐减小;腐乳成熟后硬度和弹性均变化不大;高盐含量下腐乳的硬度和弹性较大、黏着性较小。     

回用纤维表面的物理和化学变化

研究了硫酸盐浆、酸性亚硫酸盐浆、氢氧化钠浆、碱性亚硫酸盐浆1次回用后纤维的形态、纤维表面的物理及化学变化。结果表明,纸张经1次回用后,回用浆中细小纤维的含量明显增加,纤维平均长度变化不大,纤维的柔软性降低,卷曲指数和扭结指数下降;电镜分析显示,回用纤维的表面和原纤维的表面特征相似,密实光滑,但与原纤维表面相比,回用纤维暴露出较多的S2层,即纤维表面部分复合胞间层在回用过程中脱落;实验的4种浆料经回用后,纤维表面的O/C原子比均下降,氢氧化钠浆的O/C原子比下降得最多达22%,而酸性亚硫酸盐浆O/C原子比只下降3.4%。     

Chemical and Physical Changes in Red Hake Blocks During Frozen Storage

Storage stability of frozen red hake blocks over a 6-month period was studied under commercial conditions with processing modifications. The rate of DMA formation was significantly greater in samples dipped in polyphosphate and erythorbate compared to a reference (?90°C) or to a 5-day aged sample. There were no significant differences in the rate of decrease of extractable protein nitrogen over the 24-week period. A trained sensory panel found samples from aged fish to be generally more acceptable from a flavor and texture stand-point than the other treated samples. Mechanical shear forces tended to be higher for samples dipped in polyphosphate-erythorbate and lowest for 5-day samples among treated fillets. With proper handling red hake fillets may make a satisfactory commercial frozen block.