采用顶空固相微萃取结合气相色谱-质谱-嗅闻联用探讨8种市售橄榄油挥发性风味成分及其特征,并结合电子鼻甄别不同品牌及加工工艺的橄榄油。结果表明,以DVB/CAR/PDMS为萃取头,采用萃取温度60℃、平衡时间30 min及萃取时间30 min为最佳优化条件,共检出橄榄油108种挥发性成分,主要有烃类、醛类、醇类和酯类,其占总挥发性成分的84.43%～96.65%。烃类以1-十三烯、3-乙基-1,5-辛二烯为主,醛类以正己醛、（E）-2-己烯醛和壬醛为主,醇类以3-己烯-1-醇和正己醇为主,酯类以乙酸乙酯和乙酸叶醇酯为主。主要的风味贡献物质是正己醛、（E）-2-己烯醛、（E）-2-癸烯醛、壬醛、乙酸叶醇酯、乙酸己酯、乙酸乙酯、叶醇、3-己烯-1-醇、（E）-2-己烯-1-醇。特级初榨橄榄油主要香型是脂香型和橄榄果香型,而纯橄榄油主要香型为清香型。气相色谱-质谱-嗅闻联用和电子鼻结合主成分分析及判别因子分析可有效区分不同品牌和加工工艺的8种橄榄油并找出特征风味成分,可为橄榄油的溯源提供新方法。

Diabetes is a chronic metabolic diseases.As an important food ingredient and natural hypoglycemic resource,cereal can help treat and control diabetes.In this paper,the research progress of studies on functional ingredients in cereals,as corn,wheat,rice,soybeans and coarse cereals are reviewed.Also,the cause of diabetes and research status of action mechanism on active ingredients are introduced.Thus,it will help researchers for new product development of grain functional food.

随着人们生活水平和健康意识的不断提高,对高膳食纤维含量食品的需求和青睐度越来越高.为提高天然膳食纤维的品质,膳食纤维改性技术和方法的研究备受关注.其中,挤压是实现食品原料中膳食纤维改性最为理想的技术之一.在分析相关文献的基础上,从溶解性、持水力、膨胀力以及微观结构4个方面,综述了膳食纤维在挤压过程中发生的变化.同时,综述了挤压温度、机械剪切强度和含水量3个主要挤压因素对膳食纤维特性的影响规律.最后对膳食纤维挤压改性研究中存在的问题进行总结,对挤压技术在膳食纤维改性中的应用前景进行了展望.

以发芽糙米为原料,研究糙米乳制作过程中各工艺参数对最终产品的感官属性和GABA含量的影响,得出最终工艺参数:发芽糙米原料烘烤条件为160℃,5 min;通过淀粉酶、糖化酶在63℃下酶解30 min;进行100目过筛和均质;灌装后于121℃下杀菌20 min.

通过介绍糙米中γ-氨基丁酸的主要代谢途径,综述提高发芽糙米中γ-氨基丁酸含量的方法以及富γ-氨基丁酸发芽糙米产品的研究与利用现状,并分析发芽糙米需要解决的问题和发展前景.

South African Rooibos Tea is famous for its abundant of functional components. Modern studies show that Rooibos Tea has the efficient of antioxidation, antimutagen, anticancer, anti-microbial, antitoxin, and also has the function of immuno regulation, prevention of cardiovascular disease, controlling diabetes, antispasmodic gastrointestinal disease. This paper introduces in detail the chemical composition and nutrition effect of South African Rooibos Tea, provides scientific evidence for marketing promotion of Rooibos Tea.

The best technical process and formula had been acquired after studying the sugar-free gelatinized confections according to gel property and synergistic interaction of κ-carrageenan,ι-carrageenan and pectin. The best recipe of the jelly powder by the orthogonal experiment was obtained: κ-carrageenan 1.4 %, ι-carrageenan 0.5%, KCl 1.0%, CaCl2 0.6%, pectin 0.18%. It was explored that the new mixture jelly powder was conformed to be rich in dietary fiber contributing to maintain normal intestinal function and effectively reduce sweetness of jelly candy by the method of replacing sugar with poly dextrose 7%. Fish collagen peptide was proved to be the most suitable for added in the jelly according their flavor and color based on food safety and consumer cognition. The sensory analysis of jelly sweets was tested through adding fish collagen peptide into jelly candy by 3%, 4%, 5%, 6%, 7%, and the conclusion was that below 5%amount had no obvious influence on texture and flavor of jelly candy.

本文介绍了信号检测中的R-index法在8种萨拉米产品排序中的应用,针对排序结果进行了气相色谱-电子鼻联用系统(GC-O)风味分析.采用气相质谱-质谱-电子鼻联用系统(GC-MS-O)进行了相关风味成分定性,实验结果表明:烯丙基甲基硫醚、3-侧柏烯、γ-柏松油烯以及β-石竹烯可能为影响排序的主要关键风味因素.这四种成分主要存在于大蒜油及合成使用香料中,赋予产品葱蒜香,肉桂香等.同时,实验最终确定产品中的相关风味成分43个,关键风味成分18个:烯丙基甲基硫醚、甲苯、3-甲基丁酸、2-乙酰基-1-吡咯啉、3-侧柏烯、(+)-α-蒎烯、苯甲醛、β-蒎烯、辛醛、(R)-(+)-柠檬烯、苯乙醛、γ-柏松油烯、愈创木酚、芳樟醇、壬醛、樟脑、(-)-4-萜品醇、β-石竹烯.具体感官属性与GC-O结果关联需进一步研究.

从腐败的肉制品中分离得到1株产耐高温蛋白酶的细菌ZL01,根据其形态学特征、生理生化特性,并结合16S rDNA序列分析结果,发现该菌属于沙雷氏菌属.本研究结果表明,利用Nisin、双乙酸钠、山梨酸钾与Na2EDTA组合防腐剂能显著抑制沙雷氏菌ZL01的繁殖.

The effect of the size of saccharides on protein structure and antigenicity after glycation was studied. alpha-Lactalbumin (alpha-LA) was incubated in a dry state with glucose, maltose or maltooligosaccharides (up to maltopentaose), at 55 degrees C and 65% relative humidity. The extent of glycation, aggregation processes, antigenicity, glycation sites and structural changes were investigated. Structural changes were observed when the protein was incubated with larger saccharides. Furthermore, the degree of glycation decreased with an increase in the size of the saccharide. The antigenicity of all samples significantly decreased when glycation increased, but the greatest reduction of antigenicity was observed with maltotriose-alpha-LA. By comparing the glycation sites of all the glycated samples, glycation of Lys58 was dominant in glucose-alpha-LA and maltotriose-alpha-LA, whose antigenicity reductions were the highest. These results suggest that when the main epitope was glycated, the degree of antigenicity reduction increased with the increase in the size of the saccharide. (C) 2013 Published by Elsevier Ltd.

The aim of this study was to evaluate the oral safety of Lactobacillus salivarius REN, a probiotic isolated from the fecal samples of a healthy centenarian. BALB/c mice were respectively orally administered with 0, 3 x 10(8), 5 x 10(9), or 2 x 10(10) CFU/mouse daily for 28 days, or injected intraperitoneally with 5 x 10(8) CFU/mouse in a single dose, then killed at day 2 and day 5 after injection, respectively. The results indicated that oral administration of Lactobacillus salivarius REN had no adverse effects on body weight, food intake, hematological and serum biochemical parameters, and there was no treatment-associated bacterial translocation to the blood, liver, spleen, or kidney. Intraperitoneal injection caused bacterial translocation to the liver, spleen, and kidney, except blood, the translocation did not trigger illness or death. This study suggests Lactobacillus salivarius REN is likely to be safe for human consumption.

SCOPE:We assessed the effects of milk proteins and fats, alone and in combination, on the absorption of phenolic acids and the change in plasma antioxidant capacity after jujube juice intake in humans.METHODS AND RESULTS:Twenty volunteers received the following four treatments each in a 4 × 4 Latin square design with a minimum 1 week interval: 200 mL of jujube juice plus 200 mL of (1) water; (2) whole milk; (3) skimmed milk; or (4) milk fat. The results showed that skimmed milk extended the time to reach maximum increase of plasma phenolic acids concentrations and plasma antioxidant capacity. However, neither the skimmed milk nor the milk fat had a significant effect on the absorption of phenolic acids. In contrast, whole milk significantly reduced the absorption of phenolic acids and the increase in plasma antioxidant capacity (p < 0.05). In vitro results suggested the formation of complexes during digestion that involved milk proteins, milk fats, and phenolic acids, which were responsible for the inhibitory effect of whole milk.CONCLUSION:Milk proteins and fats together, but not alone, are responsible for the inhibitory effect of milk on the absorption of phenolic acids and the change in plasma antioxidant capacity.

As the constant improvement demand at feasibility and practicability of food sensory descriptive method, consequently, conventional method is facing great challenge. Recently, The trend of descriptive analysis method is in the direction of rapid and efficient. This overview concerns an investigation of the current rapid descriptive sensory methods, including the Flash Profile, Sorting Procedure, Projective Mapping, Napping, Ranking Descriptive Analysis and Optimized Descriptive Profile. Finally, advantages and disadvantages of these methods will be discussed in a comparative way and the future of descriptive sensory analysis is also forecasted.

In this study, blackcurrant fruit and leaf samples from four main cultivation regions of China were collected to analyze their carbon, nitrogen, hydrogen, and oxygen isotope compositions in order to develop an approach for tracing geographic origins of blackcurrant fruits and juice concentrates. The stable isotope compositions of the soils from these locations were also analyzed to link blackcurrant leaves and fruits with the environmental conditions they grew under. In most cases, there were significant differences in the nitrogen isotope ratios of organic matter in fruits, leaves, and topsoil as well as the hydrogen and oxygen isotope ratios of water in blackcurrant fruits and topsoil among blackcurrant from four sampling sites; thus, the four main cultivation regions of blackcurrant fruits in China could be discriminated through the combination of the stable isotope ratios of nitrogen, hydrogen, and oxygen. However, carbon isotope ratio did not offer any clue for blackcurrant geographic origin. In addition, there were positive correlations of nitrogen isotope signature between blackcurrant fruits and leaves or the topsoil (0–10 cm); thus, the isotope signature of blackcurrant leaves and the topsoil of the cropland could be good indicators of the isotope compositions of blackcurrant fruits when tracing potential geographic origins of blackcurrant fruit concentrated juices or their juice produces. Therefore, stable isotope signatures of blackcurrant materials offer great potentials for tracing geographic origins of blackcurrant fruits or their related produce in China or other cultivation regions.

As a kind of fresh cheese spread,spreadability is one of the most important textural properties of cream cheese.Renneting and acidification,as two important coagulation methods,have significant effects on spread ability.There have been great advances in understanding of the effects of acid or rennet induced coagulation on the spreadability of cream cheese,whereas less is understood about how combination of acid and rennet affects its spreadability.So the objective of the present study was to determine the effects of combined acid and rennet on the spread ability of cream cheese.Combined with texture profile analysis(TPA) and rheological technique,we investigated the effects of coagulation methods on chemical compositions,cheese yield and the spreadability of cream cheese.The coagulation methods in this research included strictly acidification with no rennet(NR),strictly renneting with no acid(NA) and combined acid and rennet with different acidification degrees,rennet with lower acid(RLA),rennet with medium acid(RMA) and rennet with higher acid(RHA).Cream cheeses with pH values near the isoelectric point exhibited higher moisture,lower fat and protein than those with higher pH values.With combination of acid and rennet,as the cutting pH rising from 4.6 to 6.1,the content of fat and protein in cheese were increased,while the water content was decreased to 47.75%.These results confirmed the remarkable effect of coagulation methods on the composition of cream cheese.On the other hand,coagulation methods also affected the cheese yield and component recoveries.In the rennet or combined acid and rennet induced cheese,there was a significant increase in the yield and component recoveries.In contrast acid-induced cream cheese had lower yield and component recoveries.This could arise from the different changes in the interactions between the casein micelles as a result of rennet and acid action in two ways.Eventually,coagulation methods changed the spreadability.RHA with the lowest shear work(19.23N·s) and yield stress(195.67 Pa) has especially remarkable in spreadability.It was found that rennet-induced cream cheese had higher hardness and was the most difficult to spread.Acid-induced cream cheese had medium spreadability.With the decrease of pH,cream cheese with a combination of acid and rennet coagulation had moderate hardness,smoother texture and was easier to spread.These results may be attributed to the complex interparticle forces in combination of acid and rennet gels.In rennet gels,casein micelles bond together through hydrophobic and Ca2+-bridging interactions while the aggregating particles coagulate through attractive interactions in the acid gels.So the forces in combination of acid and rennet gels would be different from these strictly acid or rennet gels.For the RHA gels in our research,it formed special structure with the interactions which may contain hydrophobic,Ca2+-bridging and attractive interactions.Rennet with higher acid(RHA) was the best way to produce cream cheese for better spreadability.Apparently,with the coagulation method of combined rennet and acid,the spreadability of cream cheese could be significantly improved.

The aim of this study was to evaluate the oral safety of Lactobacillus salivarius REN, a probiotic isolated from the fecal samples of a healthy centenarian. BALB/c mice were respectively orally administered with 0, 3 × 10 8 , 5 × 10 9 , or 2 × 10 10 CFU/mouse daily for 28 days, or injected intraperitoneally with 5 × 10 9 CFU/mouse in a single dose, then killed at day 2 and day 5 after injection, respectively. The results indi-cated that oral administration of Lactobacillus salivarius REN had no adverse effects on body weight, food intake, hematological and serum biochemical parameters, and there was no treatment-associated bacterial translocation to the blood, liver, spleen, or kidney. Intraperitoneal injection caused bacterial translocation to the liver, spleen, and kidney, except blood, the translocation did not trigger illness or death. This study suggests Lactobacillus salivarius REN is likely to be safe for human consumption.

Phenolics-rich foods such as fruit juices and coffee are often consumed with milk. In this study, the interactions of α-lactalbumin and β-lactoglobulin with the phenolic acids (chlorogenic acid, caffeic acid, ferulic acid, and coumalic acid) were examined. Fluorescence, CD, and FTIR spectroscopies were used to analyze the binding modes, binding constants, and the effects of complexation on the conformation of whey protein. The results showed that binding constants of each whey protein–phenolic acid interaction ranged from 4×105 to 7×106M−n and the number of binding sites n ranged from 1.28±0.13 to 1.54±0.34. Because of these interactions, the conformation of whey protein was altered, with a significant reduction in the amount of α-helix and an increase in the amounts of β-sheet and turn structures.

为找到鉴别黑加仑果汁产地的最有效指标,利用同位素比率质谱仪(IRMS)方法研究不同产地的黑加仑果实、树叶、土壤和果汁中碳和氮稳定同位素比率。结果表明:不同地区黑加仑果实中δ15N值差异显著(P<0.05),并随着地理纬度增加呈减小的趋势;部分地区的δ13C值有显著差异(P<0.05)。进一步分析发现,果汁中的碳稳定同位素比率与土壤和果实中碳稳定同位素比率具有显著性相关性(P<0.05);果汁中氮同位素比率与果实、树叶及土壤中氮同位素比率之间具有极显著相关性(P<0.01)。果实的碳和氮稳定同位素联合分析是黑加仑果汁产地溯源的最有效指标,准确率可达到86.9%;利用当地树叶和当地土壤代替果实样品进行产地区分的准确率分别达61.5%和75.0%,表明树叶和土壤亦可代替果实对黑加仑果汁进行有效的产地鉴别。