由大豆秸秆酶解液制备L-乳酸试验研究

以大豆秸秆酶解液为原料，对乳酸发酵菌株进行了筛选，并研究了利用乳酸菌发酵生产食品工业中的安全添加剂L-乳酸的发酵条件。结果表明，混合菌种发酵优于单一菌种发酵，以葡萄糖计，糖酸转化率为71．05％。     

扇贝加工下脚料发酵生产优质蛋白饲料菌种的筛选

以扇贝加工下脚料为原料,选取酵母菌、植物乳杆菌、保加利亚乳杆菌和乳酸链球菌4个菌种,采用酵母菌与乳酸菌混合发酵的方法生产优质蛋白饲料。以发酵产物中氨基态氮和粗蛋白含量为指标,对混合菌种进行筛选,并确定混合菌种的最佳比例。结果表明:酵母菌与乳酸菌混合发酵扇贝下脚料可提高其氨基态氮和粗蛋白含量,其中酵母菌、乳酸链球菌和保加利亚乳杆菌混合发酵效果最好,最佳菌种比例为3:1:1,在此条件下所得发酵产物的氨基态氮含量为3.52%,,粗蛋白含量为61.63%。     

酒糟发酵蛋白质饲料菌种筛选的研究

酒糟为发酵原料,以发酵产物粗蛋白质、真蛋白和粗纤维含量为指标,选用了8种酵母和霉菌,通过平板点种、单菌发酵及混合菌种发酵试验,筛选了酒糟发酵蛋白质饲料的最佳菌种组合.结果表明:酒糟发酵蛋白质饲料的最佳菌种组合为白地霉和热带假丝酵母、绿色木霉,与酒糟及发酵基质相比,发酵后粗蛋白质含量分别提高了41.89%及24.50%,真蛋白含量分别提高了48.89%及53.18%,粗纤维分别降低了26.65%及32.96%.     

番茄汁乳酸发酵饮料的研究

本文以番茄为原料,经加工处理,将所得原料进行乳酸发酵。首先筛选适宜于番茄汁乳酸发酵用的菌种,从产品的感官、风味、品质等总体效果评定,认为混合菌种发酵的番茄汁优于单一菌种的发酵。本研究确定了混合菌的组成、配比、接种量;探讨了发酵的最佳温度、时间;提出了番茄汁发酵的工艺流程。制品不添加任何化学防腐剂、色素和香精等。分析结果表明,该制品营养丰富,可作为保健型饮料。     

牛乳,低酚棉籽蛋白发酵制作乳酸饮料的研究

本实验主要采用牛乳、低酚棉籽蛋白为原料,以乳酸链球菌、乳酸杆菌为发酵菌种来研究单菌种和混合双茵种发酵的发酵特性,并经三因子三水平的正交实验,得到了乳酸发酵乳饮料的发酵最优工艺条件。     

纯菌接种发酵技术在腌渍蔬菜加工上的应用研究 优良乳酸发酵菌种特性的研究及菌种筛选(1)

应用纯接种乳酸发酵技术生产泡菜是对传统自然发酵模式的一种变革,也是发酵技术现代化的一种标志。本文就影响发酵质量及成败的首要因素—所收集之不同乳酸发酵菌种的生长及发酵特性进行系统比较和研究,并在此基础上筛选并确定最适的乳酸发酵菌种及其组合供扩大试验及生产之用。     

混合菌种发酵羊肉香肠理化性质的初探

选择可生产发酵肉制品的植物乳杆菌、弯曲乳杆菌、乳酸片球菌发酵剂制作羊肉发酵香肠。研究3个菌种混合下发酵羊肉香肠的理化性质。结果表明:实验组相比对照组(单一菌种发酵)的亚硝酸盐的残留量、TBA值和TVB-N值明显降低了。     

纯菌接种发酵技术在腌渍蔬菜加工上的应用研究(一) 优良乳酸发酵菌种特性的研究及菌种筛选

应用纯接种乳酸发酵技术生产泡菜是对传统自然发酵模式的一种变革，也是发酵技术现代化的一种标志。本文就影响发酵质量及成败的首要因素－所收集之不同乳酸发酵菌种的生长及发酵特性进行了系统比较和研究，并在此基础上筛选并确定了最适的乳酸发酵菌种及其组合供扩大试验及生产之用。     

多菌种在酱油酿造中的应用

我国酱油酿造自30年代开始采用单一菌种进行酿造以来,在生产实践中,人们逐渐认识到只靠单一菌种的酶系是不可能完成酱油酿造过程中一系列复杂的生化反应的,如蛋白质、淀粉、纤维素和果胶质等的降解,多种氨基酸和风味物质的生成等,从而影响了原料利用率和产品风味的提高。八十年代初以来,开展应用多菌种酿造酱油的研究,以弥补单一菌种的不足,提高原料利用率,并在短周期发酵过程中提高产品风味。这些研究主要包括以下两个方面:应用多菌种制曲,即应用多种曲霉混合制曲或分别制曲混合发酵,以丰富成曲的酶     

纯菌接种发醇技术在腌渍蔬菜加工上的应用研究优良乳酸发酵菌种特性的研究及菌种筛选（1）

应用纯接种乳酸发醇技术生产泡菜是对传统自然发酵模式的一种变革,也是发酵技术现代化的一种标志,本文就影响发酵及成败的首要因素一所收集之不同乳酸发酵菌种的生长及发酵特性进行系统比较和研究,并在此基础上筛选并确定最适的乳酸发酵菌种及其组合供扩大试验及生产之用。     

谷物与蔬菜复合食品的研究开发现状及展望

对以谷物和蔬菜为主要原料的复合食品现状进行综述,初步阐述了这类复合食品的营养价值、应用前景及发展思路。     

Production of potentially probiotic beverages using single and mixed cereal substrates fermented with lactic acid bacteria cultures

In the present work, single and mixed cereal substrates were fermented with lactic acid bacteria to study and compare the effect of the media formulation on fermentation parameters. Three cereal flours namely malt, barley and barley mixed with malt (barley–malt) were selected and fermented with two probiotic strains: Lactobacillus plantarum (NCIMB 8826) and Lactobacillus acidophilus (NCIMB 8821). The effect of the single and mixed cereal flour suspensions on the fermentation of these two strains of lactic acid bacteria (LAB) was studied at an incubation temperature of 30 °C for 28 h. It was found that the LAB growth was enhanced in media containing malt and significant amounts of lactic acid were produced (0.5–3.5 g/L). A cell concentration between 7.9 and 8.5 Log₁₀ CFU/mL and a pH below 4.0 was achieved within 6 h of fermentation. Though the cell populations in the mixed culture fermentations of mixed substrates were similar to the ones obtained with single cereal flours, significant differences in the production of lactic acid were observed. These results suggest that the functional and organoleptic properties of these cereal-based probiotic drinks could be considerably modified through changes in the substrate or inocula composition.     

A COMPARISON OF MICROBIOLOGICAL AND RADIOIMMUNOASSAY METHODS FOR THE DETERMINATION OF PANTOTHENIC ACID IN FOODS

Seventy-five foods were analyzed for the vitamin pantothenic acid using a microbiological assay and a new radioimmunoassay (RIA). The food sample extract used in both assays was the result of dialysis after enzyme hydrolysis. In the method used previously, the food-enzyme mixture had been filtered.
A very high correlation (r²=.94) between the results from the RIA and the microbiological assay was found. There was a statistically significant difference between the two assay results for all foods and for the subgroups meats, breads and cereals, and fruits and vegetables at p=.05. At p = .01 breads and cereals and fruits and vegetables did not have significantly different results between the two assay methods. For all foods and all subgroups, the microbiological assay produced a higher mean result than the RIA.
The RIA is an acceptable method for assaying pantothenic acid in breads and cereals and fruits and vegetables. Futher study is needed to determine how components of meat interact with one or both assay systems.     

Preliminary enzymolysis studies on trace element extractability from food

A preliminary investigation into the availability to man of some trace elements in foodstuffs is reported. The amounts of soluble lead, cadmium, zinc, iron and copper after a simulated digestion procedure, were measured in cereals, meats, fish and non-root vegetables consumed in UK. Details of the enzymolysis procedure and acid digestion method are given. The results show that the amount of soluble analyte varies widely from element to element and according to food type. When added to food the behaviour of soluble inorganic forms of the elements is often markedly different to that of the endogenous elements. The implications of some of these differences are considered.     

溶剂吸收-气质联用法测定蔬菜和粮谷中代森铵残留

目的建立一种测定蔬菜和粮谷中代森铵残留量的溶剂吸收-气相色谱-质谱(gas chromatographymass spectrometry,GC-MS)联用测定法。方法样品在氯化亚锡盐酸溶液中加热反应,生成二硫化碳气体经正己烷吸收,用气质联用仪测定。结果添加代森铵浓度水平为0.03、0.3、0.6mg/kg,平均回收率在75.7%~91.0%,相对标准偏差在4.2%~9.1%,定量限为0.03mg/kg。结论建立的方法灵敏度高,特异性好,为农产品中二硫代氨基甲酸酯类农药残留量监测提供又一可靠的测定方法选择。     

北京市海淀区部分餐馆直接入口食品及餐具食源性致病菌监测结果分析

目的:掌握北京市海淀区餐饮业直接入口食品卫生状况,为卫生行政部门制定相应监督、监测方案提供依据。方法:采集119家餐饮单位直接入口食品,包括凉拌菜、炝拌菜、沙拉、熟肉制品、生食或半生食的水产品、糕点面包、江米制品、水果拼盘、鲜榨果蔬汁、爆炒菜、盒饭等,依据GB14934-1994、GB/T4789-2003和WS/T9-1996等国标方法检测,统计用χ2检验。结果:2737件样品中大肠菌群合格率82.10%,各种直接入口食品中大肠菌群合格率差异有统计学意义(χ2=23.67,P<0.001),鲜榨果蔬汁、炝拌菜、凉拌菜、熟肉制品合格率较低,分别为72.34%、76.81%、78.58%、79.79%。致病菌检出率为:变形杆菌3.72%、金黄色葡萄球菌2.37%、单核细胞增生李斯特氏菌2.03%、肠致病性大肠埃希氏菌0.68%、沙门氏菌0.08%,各种致病菌检出率差异有统计学意义(χ2=111.97,P<0.001)。未检出志贺氏菌、肠出血性大肠埃希氏菌O157∶H7和副溶血性弧菌。各类餐饮企业中2 737件食品样品检测合格率为86.02%,各类餐饮企业中食品样品检测合格率差异有统计学意义(χ2=23.67,P<0.001),火锅店、日餐、普通餐馆合格率较低,分别为54.84%、75.00%、71.23%。2 875件餐饮具中大肠菌群合格率为86.02%,各类餐饮企业餐饮具中大肠菌群合格率差异有统计学意义(χ2=160.57,P<0.001),火锅店、日餐、普通餐馆合格率较低,分别为53.85%、80.00%、80.82%。结论:直接入口食品存在不同程度的细菌污染,是引起食物中毒和食源性疾病的隐患,应该加强对餐饮单位直接入口食品卫生的监测。     

Arsenic and lead in foods: a potential threat to human health in Bangladesh

The non-carcinogenic and carcinogenic risk of arsenic and lead to adults and children via daily dietary intake of food composites in Bangladesh was estimated. The target hazard quotients (THQs), hazard index (HI) and target carcinogenic risk (TR) were calculated to evaluate the non-carcinogenic and carcinogenic health risk from arsenic and lead. Most of the individual food composites contain a considerable amount of arsenic and lead. The highest mean concentrations of arsenic were found in cereals (0.254 mg kg^–1 fw) and vegetables (0.250 mg kg^–1 fw), and lead in vegetables (0.714 mg kg^–1 fw) and fish (0.326 mg kg^–1 fw). The results showed the highest THQs of arsenic in cereals and lead in vegetables for both adults and children which exceeded the safe limit (> 1) indicating that cereals and vegetables are the main food items contributing to the potential health risk. The estimated TR from ingesting dietary arsenic and lead from most of the foods exceeded 10^?6, indicating carcinogenic risks for all adult people of the study area.     

Selection and use of autochthonous mixed starter for lactic acid fermentation of carrots, French beans or marrows

Strains of Leuconostoc mesenteroides, Lactobacillus plantarum, Weissella soli/Weissella koreensis, Enterococcus faecalis, Pediococcus pentosaceus and Lactobacillus fermentum were identified from raw carrots, French beans and marrows by partial 16S rRNA gene sequence. L. plantarum M1, Leuc. mesenteroides C1 and P. pentosaceus F4 were selected based on the rates of growth and acidification in vegetable juice media, and used as the autochthonous mixed starter for the fermentation of carrots, French beans or marrows. An allochthonous starter, consisting of the same species, was also used for fermentation. A two-step fermentation process (1 day at 25 degrees C and 7 days at 15 degrees C) in brine (1% w/v) followed by storage at room temperature in olive oil until 40 days was set up. Unstarted vegetables subjected to the same treatments were used as the controls. Cell numbers of lactic acid bacteria in the started vegetables were ca. 10,000 (autochthonous starter) and 1000 (allochthonous starter) times higher than unstarted samples throughout the process. When fermented with the autochthonous starter, carrots, French beans or marrows were characterized by the rapid decrease of pH (<4.5), marked consumption of fermentable carbohydrates, and inhibition of Enterobacteriaceae and yeasts. Fermentation with the allochthonous starter did not acidify and inhibit bacteria and yeasts so rapidly. After 40 days, carrots, French beans and marrows fermented with the autochthonous starter had significantly (P<0.05) higher total concentration of vitamin C (ascorbate+dehydroascorbate) with respect to those fermented with the allochthonous starter and, especially unstarted vegetables. The same was found for the indexes of color. Firmness of both started vegetables was higher than unstarted vegetables. Sensory analysis differentiated started vegetables. Carrots and French beans fermented with the autochthonous starter were, especially, appreciated for fragrance. Appearance was the sensory attribute that mainly distinguished marrows fermented with the autochthonous starter.     

The composition of Indian foods—mineral composition and intakes of Indian vegetarian populations

The trace element (Fe, Mn, Zn and Cu) and Ca and P contents of cereals, legume grains, vegetables, milk products and oilseeds commonly consumed by Indian vegetarians were determined. Green leafy vegetables contained the highest amounts of Fe, Mn and Cu (15–171, 90–133 and 4–21 mg kg^?1, respectively); buffalo milk, buttermilk and curd contained most zinc (53–63 mg kg^?J). Legumes contained the highest levels of P, whilst buffalo milk and curd, and leafy vegetables possessed most Ca. The levels of these elements in prepared foods and diets were entirely consistent with the above findings. In general, the mineral intakes of the populations of children (4–9 years), adolescents (10–19), adults (20–45) and older adults (45–60) examined in this study were lower for Zn and Ca, similar for Fe and Ca, and higher for Mn and P than the recently prescribed Indian Recommended Dietary Allowances (RDAs). It is likely that other constituents of cereals and pulses, such as fibre and phytate, will greatly reduce the bioavailability of trace minerals and Ca in Indian vegetarian diets. In contrast to earlier studies, no significant overall differences were observed between populations from farming and non-farming backgrounds.     

培养条件对食品中乳酸菌检验结果的影响

对市售四种不同的乳酸菌饮品,分别采用3种不同厂家的MRS培养基,在厌氧和常规需氧的条件下培养,得出乳酸菌的计数结果,并进行差异性分析和产生差异原因的探究.结果表明:三种培养基的计数结果存在显著性差异(P<0.05),两种培养条件下的计数结果也有一定的差异,但并不显著(P>0.05),厌氧条件下计数结果较高.样品中添加乳...