CHANGES IN MOLECULAR SPECIES COMPOSITIONS OF GLYCEROPHOSPHOLIPIDS IN THE ADDUCTOR MUSCLE OF THE GIANT EZO SCALLOP PATINOPECTEN YESSOENSIS DURING FROZEN STORAGE

Changes in lipid components, particularly glycerophospholipids, in the adducto; muscle of giant ezo scallop during storage at −20C were investigated. During storage, the contents of total lipids (TL) and polar lipids (PL) decreased, but that of nonpolar lipids increased. Thiobarbituric acid reactive substances and peroxide values of the TL increased with duration of storage. Glycerylphosphorylcholine (GPC) and glycerylphosphrylethanolamine (GPE) decomposed considerably during storage, and decreased by 50% and 15% of the initial content, while lyso-PC (LPC) and free fatty acids (FFA) increased, respectively. The percentages of polyunsaturated fatty acids (PUFAs) such as 20:5n-3 and 22:6n-3 in the TL and PL during storage decreased, however, those of the PUPAs in the NL increased. Diacylglycerylphosphorylcholine (diacyl-GPC) and diacylglycerylophosphorylethanolamine (diacyl-GPE), major components in the GPC and GPE subclasses, showed a marked decrease with duration of storage. Particularly, diacyl-GPC decreased by 68% of the initial contents of the PL. In the alkenylacyl-GPE and diacyl-GPC, the percentages of the molecular species having longer hydrocarbon chains on the sn-l positions of glycerol moieties decreased at     

The influence of douchi starter cultures on the composition of extractive components, microbiological activity, and sensory properties of fermented fish pastes

Three experiments were conducted to test the hypothesis that douchi cultures could serve as a potential starter for enhancing the quality attributes of fermented silver carp meat. In experiment 1, an active, prefermented douchi culture was incorporated into a fish paste to aid in the fish fermentation (30 d) and facilitate biochemical production of extractive flavor components (PRF). In experiment 2, a fully fermented (30 d) douchi was added to a fish paste and the mixture was fermented for 30 d (PSF). In experiment 3, a fish paste without the douchi culture was fermented for 30 d (CF). Total extracted free amino acids increased by 68.0, 68.6, and 78.8% (P < 0.05) from their initial levels to 2930, 2422, and 1573 mg/mL after 30 d of fermentation for PRF, PSF, and CF fish pastes, respectively, of which, glutamic acid, aspartic acid, alanine, lysine, and leucine were the major amino acids (>100 mg/mL). The concentrations of both formaldehyde-reactive nitrogen and ammonia nitrogen extractives increased significantly (P < 0.05) during fermentation, following the order of PRF > PSF > CF. Low amounts of biogenic amines (<25 ppm) were produced in all samples. Sensory panel evaluation showed that PRF fish pastes had desirable aroma and taste. The douchi-inoculated fermentation could be a novel technique for expanding the utilization, consumption, and the economic values of silver carp meats. Practical Application: Douchi, a fermented soybean product, is a traditional food flavoring ingredient commonly used in China, Japan, and other Asian countries. It is also used in many Chinese cuisines in the United States. On the other hand, fermented seafood made from freshwater fish such as silver carp is known to contain bioactive components believed to promote health. The findings from the present study indicated that douchi as a novel starter can be used to produce fermented silver carp fish pastes with excellent flavor and consumer acceptability. The results may be applicable to other fish species to produce similar fermentation products.     

干酪乳杆菌纯种发酵燕麦乳工艺及其产品质量分析

针对目前益生菌发酵乳制品多为混合菌种发酵动物源乳制品的研究现状,本研究以燕麦为主要原料,通过制备纯燕麦乳,酶解,添加20％牛乳和7％蔗糖以及适量乳化剂与稳定剂,组成发酵培养基,以发酵乳制品中选育出的生长繁殖力强,发酵活力高的干酪乳杆菌05-20为试验菌株,研究接种量、发酵温度、发酵时间等单因素对干酪乳杆菌纯种发酵燕麦乳...     

Effect of malting and fermentation on antinutrients,and total and extractable minerals of high and low phytate corn genotypes

Two corn genotypes, Var‐113 (high phytate) and TL‐98B‐6225‐9 × TL617 (low phytate), were germinated for 6 days. The germinated grains were dried and milled. A mixture of 5% malt and 95% corn flour was fermented for 14 days. Phytic acid and polyphenol contents and hydrochloric acid (HCl) extractability of minerals from the fermented flours were determined at the intervals of 2 days during fermentation. Phytic acid and polyphenol contents decreased significantly (P ≤ 0.05) with an increase in fermentation time, with a concomitant increase in HCl‐extractable minerals. For both genotypes, the major mineral content was increased, while that of trace minerals was increased but at slow rate with fermentation time. When the grains were fermented for 14 days, TL‐98B‐6225‐9 × TL617 genotype had higher extractable calcium and Var‐113 had higher extractable phosphorus, whereas iron and manganese recorded high extractability levels in Var‐113. There was good correlation between phytate and polyphenol level reduction and the increment in extractable minerals with fermentation time.     

Oxidation stability and compositional characteristics of oils from microwave roasted pumpkin seeds during thermal oxidation

The oxidative stability and compositional characteristics of the pumpkin seed oil (PSO) exposed to microwaves were studied during heating at 170°C. The oxidative indices such as free fatty acid (FFA), peroxide value (PV), p-anisidine value (p-AV), TOTOX, specific extinctions and thiobarbituric acid (TBA) value of oils were significantly increased, and the increments were found to be significantly higher (P < 0.05) in unroasted seed oil as compared to roasted seed oil. The relative contents of polyunsaturated fatty acids (PUFAs) were decreased to 84.7%, and saturated fatty acids (SFAs) were increased to 119.5% in unroasted sample, after 9 h of heating. On the other hand, in 12 min roasted samples, the relative contents of PUFAs were decreased to 97.0%, and SFAs were increased to 102.6% after 9 h of heating. The triacylglycerol species LLL and OLL levels were decreased as a consequence of increased heating time, and the reduction tended to be significantly higher in unroasted samples as compared to roasted ones. The oxidation products formed were also investigated by FTIR. The present results indicated that microwave roasting of pumpkin seeds markedly enhanced the oxidative stability of the oils during heating.     

Oxidative stability of frozen-stored raw pork chops, chill-stored pre-frozen raw pork chops, and frozen-stored pre-cooked sausages in relation to dietary CuSO4, rapeseed oil and vitamin E

 Danish Landrace× Danish Yorkshire female pigs were fed either a standard diet or a standard diet enriched with 6% rapeseed oil and supplemented with increasing amounts of vitamin E (0, 100 or 200 mg all-rac-α-tocopheryl acetate/kg feed) and copper (0, 35 or 175 mg CuSO₄/kg feed), and the effect of dietary regimen on the oxidative stability of (1) frozen-stored raw pork chops packed in atmospheric air, (2) chill-stored pre-frozen pork chops packed in atmospheric air, and (3) freezer-stored, vacuum-packed pre-cooked sausages was investigated. The addition of 6% rapeseed oil did not influence the oxidative stability of the pork chops negatively, whereas the oxidative stability of a product such as the pre-cooked sausages (Danish dinner sausages) with a higher fat content (15%) decreased as a result of rapeseed oil feeding. Inclusion of rapeseed oil in the diets increased the amount of monounsaturated fatty acids and polyunsaturated fatty acids (PUFAs) in the meat and fat for the production of sausages at the expense of the content of the saturated fatty acids, and the higher content of PUFAs readily explains the decreased oxidative stability of the pre-cooked sausages. Feeding pigs 100 mg or 200 mg all-rac-α-tocopheryl acetate/kg feed significantly increased the oxidative stability of the pork chops and the detrimental effect of rapeseed oil observed in the pre-cooked sausages was effectively neutralised by both levels of vitamin E supplementation. Supplementation with copper did not affect the oxidative stability of any of the products. The presented results show that it is possible to produce pork products with a nutritionally improved fatty acid profile by inclusion of 6% rapeseed oil, without affecting the oxidative stability of the products negatively, through the protection provided by dietary vitamin E. Received: 23 March 1998 / Revised version: 28 May 1998     

Effects of koji fermented phenolic compounds on the oxidative stability of fish miso

In the present study, Aspergillus oryzae-inoculated koji inhibited lipid oxidation in fermented fish paste rich in polyunsaturated fatty acids following a long fermentation period. The fermentation of koji by A. oryzae liberated several bioactive phenolic compounds, including kojic acid and ferulic acid, which were the most abundant. A linear correlation between several phenolic compounds and their bioactive properties, including their radical-scavenging activity, reducing power, metal-chelating activity, and ability to inhibit linoleic acid oxidation was observed. This suggested an important role of koji phenolics in the oxidative stability of fermented fish paste. The activities of different carbohydrate-cleaving enzymes, including α-amylase, cellulase, and β-glucosidase, were positively correlated with the liberation of several phenolic compounds through koji fermentation. Thus, the application of koji offers a novel strategy to enhance the oxidative stability of newly developed fermented fish miso. PRACTICAL APPLICATION: Application of traditional Japanese koji fermentation technique to develop an aroma enriched fish meat bases seasoning has been established. Aspergillus oryzae-inoculated koji releases several carbohydrate-cleaving enzymes, including α-amylase, cellulose, and β-glucosidase, which led to the liberation of several phenolic compounds during fermentation. Improvement of oxidative stability of the fermented fish meat paste by koji phenolics suggests a useful strategy to uplift the value of different trash fish meat-based seasoning through proper utilization of the present technique.     

Studies on production of a ghee-like product from vegetable fats

A typical ghee flavour was obtained by heating vegetable fats with fermented milk or fermented whey at 125°C for 2 min. The resulting product had an acceptability preference and better storage stability than the untreated vegetable fat. It is suggested that whey proteins and fermentation products are the major contributors to development of ghee flavour in vegetable fats. The increase in storage stability could be due to the formation of reactive sulphydryl groups from whey proteins during the heating process.     

Headspace volatiles along with other instrumental and sensory analyses as indices of maturation of horse mackerel miso

Development of aroma-active compounds during fermentation in the preparation of fermented fish-meat paste product (fish miso) from horse mackerel meat was quantitatively determined and characterized by olfactometric and organoleptic assessments. The critical ripening time was estimated by quantitative and/or qualitative analyses of volatile compounds, peptides, amino acids, product color, and total phenolics of the fish miso matrix throughout fermentation. The results confirmed that the application of koji for the fermentation of horse mackerel meat to produce fish miso significantly reduced the fishy off odor and promoted the development of highly acceptable fish miso with a nutty, cheesy, and fruity aroma. Ethyl acetate, ethyl heptanoate, ethyl decanoate, 2-methylpropanal, 3-methylbutanal, 2,3-butanedione, dimethyl trisulfide, and 3-(methylthio) propanal were identified as key odor-active compounds in fish miso prepared from horse mackerel meat. Among the volatiles, 2-methylpropanal, 3-methylbutanal, and 2,3-butanedione were identified to serve as potential indicators of the maturation of fish miso. Amino acid content could also be a potential indicator of maturation of protein-rich, fermented products such as fish miso. In addition, surface color analysis of fish miso revealed a high correlation between sensory attributes and color components. Specifically, r and b values were considered potential indicators of maturation. Practical Application: Variability is a major drawback in fermented products such as fish miso and it requires establishing the optimum ripening time, defined as that providing the aroma attributes qualitatively and quantitatively mostly appreciated by consumers. We have carried out this work for comprehensive determination of the critical ripening time by applying several instrumental and sensory tools including quantitative and/or qualitative analysis of volatile compounds, peptides, amino acids, product color, and total phenolics of the fish miso matrix throughout the fermentation period. The outcome of the present study can be efficiently applied for detection of maturation in similar types of fermented product for large-scale production.     

乳酸菌发酵核桃酸乳不良气味的形成与分析

目的：为探究核桃发酵酸乳不良气味物的形成机制及其组成,改善其风味品质。方法：采用对比实验和感官评价分析不同发酵剂、不同原料组分对发酵乳不良气味产生的影响,研究核桃乳发酵过程中原料组分、羰基价与挥发性化合物的变化规律与相关性;采用顶空-固相微萃取-气相色谱-质谱联用技术分析核桃酸乳挥发性化合物组成,采用相对气味活度值和主成分分析法对关键性风味物和不良气味物进行分析。结果：原料中脂肪组分与不良气味产生显著相关,发酵过程中酸乳羰基价与不良气味形成显著相关;核桃酸乳主要的挥发性风味物包括：己酸等3种酸类化合物,乙偶姻等3种酮类物,正己醇等7种醇类化合物,(E)-2-庚烯醛等4种醛类化合物以及丁酸丁酯和其他类化合物;相对气味活度值大于1的挥发物为(E)-2-庚烯醛、乙偶姻、己酸、正己醇、正辛醇、1-庚醇、苯甲醛、2-壬酮、2-庚酮、苯乙烯和苯乙醇;关键风味物为乙偶姻、己酸、(E)-2-庚烯醛、正己醇。结论：己酸、(E)-2-庚烯醛、正己醇、苯甲醛为核桃酸乳不良气味的主要风味物,其形成的主要路径为核桃乳发酵过程脂肪水解产生较多的亚油酸、亚麻酸,在脂肪氧合酶作用下氧化,裂解产生C6～C9的醇、醛、酸...     

传统发酵豆制品生产过程中的安全隐患及改进措施

我国传统的发酵豆制品是以富含植物蛋白的大豆、豆粕等为主要原料,通过发酵微生物酶的作用,发酵水解生成多种氨基酸、各种糖及多种小分子化合物,在经过复杂的生物化学变化形成的各种发酵制品,包括腐乳、豆豉、豆酱、酱油等。传统发酵豆制品具有独特的风味、丰富的营养和保健功能深受大众喜爱。然而,传统发酵豆制品特殊的生产方式使在其原料加工、发酵生产、运输、贮藏过程中存在安全隐患,影响产品质量的稳定性和食用的安全性,因此发酵豆制品的食品安全性成为了目前研究的热点问题之一。文章从传统发酵豆制品的主要种类、产品风味及生产工艺特点,生产原料的安全性问题,发酵微生物的安全性问题,发酵代谢产物的安全性问题等方面对传统发酵豆的生产过程及其产物的安全控制因素的现状和不足进行了分析,并指出了发酵豆制品生产安全控制的改进措施,旨在为相关企业生产管理提供参考。     

不同菌种发酵大蒜液的品质比较分析

为研究不同菌种对发酵大蒜液品质的影响,对大蒜发酵过程中总酚、可滴定酸、甲醇、乙醇等理化指标和羟基自由基清除能力进行监测,利用高效液相色谱法分析其有机酸种类及其含量,采用电子舌分析不同发酵时间发酵大蒜的味感变化.结果表明,不同菌种(酿酒酵母或植物乳杆菌)发酵制备的大蒜液,在其发酵过程中,总酚、可滴定酸均呈现上升的趋势,发...     

AMINO ACID COMPOSITION AND NUTRITIONAL IMPLICATIONS OF MILK FERMENTED BY VARIOUS LACTIC CULTURES

A total of nine milk products were analyzed for total and free amino acids and total and nonprotein nitrogen. The products were: (1) whole milk (WM), (2) skim milk (SM), (3) WM fermented by Streptococcus thermophilus, (4) SM fermented by S. thermophilus, (5) WM fermented by Lactobacillus bulgaricus, (6) SM fermented by L. bulgaricus, (7) WM fermented by L. acidophilus, (8) SM fermented by L. acidophilus and (9) commercially prepared buttermilk. Essential amino acid content of the fermented milk was lower than that of the whole or skim milk. Fermentation of milk by lactic cultures decreased the total lysine (except butter milk) and methionine contents of all the samples. Since these two amino acids are limiting amino acids in protein malnourished areas, lactic fermentation of milk may be undesirable based on the chemical scores of the protein. However, the free amino acid content, including that of lysine and methionine, increases significantly upon lactic fermentation of milk. This predigestion of protein might result in an increased availability of the amino acids to offset the reduction in amino acids during fermentation and may even result in a better quality protein. Biological evaluation of the fermented milk proteins is necessary to evaluate their nutritional quality. L. bulgaricus was the most proteolytic of all the organisms used.     

鲊辣椒纯种发酵的菌株优选

通过对市售鲊辣椒样品中微生物的分离、鉴定,确定鲊辣椒发酵过程中的主发酵菌;再购买常用的几种发酵菌,通过其在最适条件下的产酸性和还原糖利用率等对菌株进行初筛;在初筛的基础上,再在实际生产中用产酸性、氨基酸态氮的生成和发酵成品的感官评分实验对其进行复筛。结果表明：鲊辣椒自然发酵过程中的主发酵菌是乳酸菌,纯种发酵的合适菌种是植物乳杆菌。纯种发酵弥补了传统自然发酵稳定性差,生产周期长等不足,可为实现鲊辣椒产品的工业化生产提供参考。     

红曲菌发酵对广式腊肠颜色和蛋白质降解的影响

采用GIM3.439紫红曲菌发酵广式腊肠,研究红曲菌发酵对广式腊肠的色泽、p H、氨基酸态氮含量和感官品质的影响;运用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳（SDS-PAGE）和高效液相色谱（HPLC）等方法对广式腊肠中蛋白质、肽、游离氨基酸进行检测,分析红曲菌发酵过程中广式腊肠蛋白质的降解,初步研究了红曲菌发酵对广式腊肠中游离氨基酸的影响。结果表明:红曲菌发酵能够加深广式腊肠的红色;在发酵6 h时,发酵组氨基酸态氮含量达0.14%;电泳结果表明,红曲菌发酵对水溶性和盐溶性大分子蛋白降解均有促进作用,能够增加产品中小分子肽及游离氨基酸的总量;游离氨基酸总量由580 mg/100 g增加到930 mg/100 g。红曲菌发酵不仅使产品色泽更加诱人,而且使发酵后腊肠滋味更加丰富、浓郁,提高了腊肠的感官品质和营养价值。      

玉米淀粉深层发酵生产L－乳酸

本文报道了使用米根霉（ＲｈｉｚｏｐｕｓＯｒｙｚａｅ）ＴＬ－５２７－９菌株用玉米淀粉深层发酵生产Ｌ－乳酸。探讨了不同碳源、氮源、底物浓度、液化条件、通气量、种龄对Ｌ－乳酸生成的影响，在３Ｍ３发酵罐中，当玉米淀粉投料浓度为１３％时，７罐平均产Ｌ－乳酸９．４１ｇ／１００ｍｌ，对糖转化率７９．５５％。发酵液经分离提取精制，Ｌ－乳酸纯度达９８％以上。同时在研究过程中利用高压液相色谱测定了Ｌ－乳酸代谢变化。本结果表明米根霉ＴＬ－５２７－９菌株具有Ｌ－乳酸产率高和发酵快的特点。     

发酵对西兰花硫代葡萄糖苷缓解秀丽隐杆线虫氧化损伤的影响

为探讨乳酸菌发酵对西兰花硫代葡萄糖苷（简称硫苷）抗氧化能力的影响，本研究以植物乳杆菌发酵西兰花，测定硫苷的代谢产物组分和体外抗氧化能力。同时，考察发酵硫苷对秀丽隐杆线虫抗应激能力和抗氧化指标的影响。结果表明，乳酸菌发酵增强了西兰花硫苷体外抗氧化能力。线虫实验显示发酵硫苷能够提高秀丽隐杆线虫在热应激和氧化应激下的存活率，显著降低线虫体内活性氧和脂褐素水平（P<0.05），提高超氧化物歧化酶活力，从而缓解线虫氧化损伤。通过乳酸菌发酵可以提高西兰花硫苷的抗氧化活性，为西兰花等十字花科蔬菜中硫苷的开发利用提供理论支撑。     

嗜根考克氏菌K45对发酵猪肉品质的影响

为了研究嗜根考克氏菌（Kocuria rhizophila）K45对发酵猪肉品质的影响，以自然发酵肉为对照组，通过测定发酵组的色度、挥发性风味化合物和游离氨基酸等探究菌株K45对发酵肉品质的影响。结果表明，菌株K45发酵组红度a*值显著高于自然发酵组（P<0.05），添加菌株K45能促进发酵肉发色；游离氨基酸含量为（365.97±3.68）mg/100 g，显著高于自然发酵组（P<0.05）；两组发酵肉中共检测到136种挥发性风味物质，菌株K45发酵组中检测到131种，有8种挥发性物质仅在菌株K45发酵组被检出，说明菌株K45可以促进发酵肉滋味和香味的形成。通过火山图分析结合相对气味活度值（ROAV）结果，发现菌株K45发酵组的特征性风味物质为双乙酰、三甲基吡嗪、2,5-二甲基吡嗪、3-甲基丁醛、2-甲基丁酸乙酯、2,3-二甲基吡嗪和萘；特征呈味氨基酸为天冬氨酸、谷氨酸、甘氨酸、精氨酸和酪氨酸。综上，接种菌株K45发酵可改善发酵肉制品的色泽和整体风味。     

Effect of Monascus Fermentation on the Characteristics of Mackerel Mince

ABSTRACT: To improve the characteristics of fish muscle, Monascus purpureus or Monascus species was inoculated in 2.1% rice powder broth containing 30% minced mackerel tissue to produce a fermented fish product. Enterbacteriaceae, Staphylococcus , and Pseudomonas were not present during the 7 d of fermentation at 25 °C. The activities of both amylase and acidic proteases were detected after 1 and 2 d of fermentation, respectively, and further increased during fermentation. The volatile base nitrogen of all Monascus fermented samples were lower than the limit of food regulation in Taiwan (< 25 mg/100 g) even after 7 d of fermentation. Hydrolysis of the muscle protein and accumulation of free amino acid were observed. The fermented fish products had good flavor and color that were highly likeable to the sensory panel.     

Changes in composition of lipids,free amino acids and organic acids in rice-bran-fermented- sardine (Etrumeus teres) during processing and subsequent storage

Changes in composition of lipids, free amino acids and organic acids in rice-bran-fermented sardine—one of the traditional marine products of Japan—were investigated. The moisture content decreased rapidly during pre-curing and then slowly during rice bran fermentation. The salt content of the finished product was about 234 g kg⁻¹ on a dry weight basis. The pH decreased from 6.1 in the raw sardine to 5.3 in the finished product. Total volatile basic nitrogen increased up to 1.0 g kg⁻¹ after 2 months of rice bran fermentation and then remained almost unchanged. Most free amino acids except histidine and taurine increased during rice bran fermentation. The histamine content increased to 0.75 g kg⁻¹ at 2 months of rice bran fermentation and subsequently decreased gradually. Certain polyamines also accumulated on relatively lower levels. Lactic acid (8.14 g kg⁻¹ at 2 months of rice bran fermentation) was a prominent organic acid produced during processing. Considerable decompositions of triglyceride and phospholipids occurred accompanied by production and accumulation of a correspondingly high concentration of free fatty acids. The peroxide value and the amount of thiobarbituric acid reactive substances in the extracted total lipids decreased gradually during rice bran fermentation. It was concluded that lipid oxidation was restricted during rice bran fermentation although remarkable proteolysis occurred. The present traditional manufacturing process seems to be applicable to the technology of processing and subsequent preservation of fish products in the developing countries.