葡萄酒有机酸研究现状及应用展望

有机酸成分研究是探索葡萄酒中呈味物质与地域环境、酿酒工艺、葡萄酒质量等关系的重要手段。本文介绍了葡萄酒中主要有机酸种类及其在发酵过程中的变化,综述了葡萄酒中有机酸的分析检测方法,并对葡萄酒中有机酸成分研究的发展趋势及应用进行了展望。      

葡萄酒有机酸研究现状及应用展望

有机酸成分研究是探索葡萄酒中呈味物质与地域环境、酿酒工艺、葡萄酒质量等关系的重要手段。本文介绍了葡萄酒中主要有机酸种类及其在发酵过程中的变化,综述了葡萄酒中有机酸的分析检测方法,并对葡萄酒中有机酸成分研究的发展趋势及应用进行了展望。     

Rapid and quantitative detection of the microbial spoilage of muscle foods: current status and future trends

The requirement for real-time monitoring in the modern and highly automated food processing environment has stimulated research into rapid microbiological testing. This review will concentrate on the search for a rapid detection system for the microbial spoilage of meats that has been ongoing since at least the 1970s. The metabolic processes and bacteria involved within the microbial spoilage of muscle foods will be outlined prior to a detailed overview of the current methods employed in the industry to quantify levels of spoilage organisms. Despite these detailed microbiological studies there is still a requirement within the food industry for new techniques which would ideally be accurate, non-destructive and give answers in real-time and a range of novel analytical technologies which are currently being developed for the rapid assessment of microbial spoilage in muscle foods will be examined.     

Bioactive compounds in bamboo shoots: health benefits and prospects for developing functional foods

Juvenile bamboo shoots have long been used as food and in traditional medicine in many Asian countries, but scientific evidences of its health benefits have been highlighted recently. According to ancient Chinese medicinal books, the consumption of young shoots helps in improving digestion, relieving hypertension, sweating, preventing cardiovascular diseases and cancer. The young shoots are delicious and rich in nutrient components such as proteins, carbohydrates, minerals and vitamins and bioactive compounds. The health benefits of the young shoots are attributed to the presence of bioactive compounds mainly phenols, phytosterols and dietary fibres, which play a potential role in health promotion and providing protection against many chronic and degenerative diseases. Phenolic compounds in bamboos have multiple biological effects such as antioxidation, anti‐ageing, antifatigue, antimicrobial and prevention of cardiovascular diseases. Dietary fibres and phytosterols have a beneficial effect on lipid profile and bowel function and reduce total serum cholesterol and low‐density lipoprotein cholesterol level. This study discusses the bioactive compounds in bamboo shoots and how, due to its nutritive value and health benefits, the shoots can be utilised as an ingredient in the development of functional foods.     

Physiological and mathematical aspects in setting criteria for decontamination of foods by physical means

In heat processing, microbial inactivation is traditionally described as log-linear. As a general rule, the relation between rate of inactivation and temperature is also described as a log-linear relation. The model is also sometimes applied in pressure and in pulsed electric field (PEF) processing. The model has proven its value by the excellent safety record of the last 80 years, but there are many deviations from log-linearity. This could lead to either over-processing or under-processing resulting in safety problems or, more likely, spoilage problems. As there is a need for minimal processing, accurate information of the inactivation kinetics is badly needed. To predict inactivation more precisely, models have been developed that can cope with deviations of linearity. As extremely low probabilities of survival must be predicted, extrapolation is almost always necessary. However, extrapolation is hardly possible without knowledge of the nature of nonlinearity. Therefore, knowledge of the physiology of inactivation is necessary. This paper discusses the physiology of denaturation by heat, high pressure and pulse electric field. After discussion of the physiological aspects, the various aspects of the development of inactivation models will be addressed. Both general and more specific aspects are discussed such as choice of test strains, effect of the culture conditions, conditions during processing and recovery conditions and mathematical modelling of inactivation. In addition to lethal inactivation, attention will be paid to sublethal inactivation because of its relevance to food preservation. Finally, the principles of quantitative microbiological risk assessment are briefly mentioned to show how appropriate inactivation criteria can be set.     

Use of organic acids for protecting moist wheat grains from microbial colonization during storage

Moist wheat grains (18% w/v) were treated with a 40:40:20 mixture of organic acids (acetic:propionic:butyric) and proprionic acid alone at 1.5 and 5.0% concentrations. The 1.5% concentration was ineffective. The 5.0% concentration protected them from various fungi for the first 6 months of storage. Later, this protective effect gradually declined. The percentage of aflatoxin-producing isolates of Aspergillus flavus on the stored grains was not affected by any of the acid treatments.     

Integrating end-user preferences into breeding programmes for roots,tubers and bananas

“Consumers have their say: assessing preferred quality traits of roots, tubers and cooking bananas, and implications for breeding” special issue, brings together new knowledge about quality traits required for roots, tubers and bananas (RTB) varieties to successfully meet diverse user preferences and expectations, along the variety development and RTB value chains (production, processing, marketing, food preparation, consumption). Key RTB crops in sub-Saharan Africa are cassava, yams, sweetpotatoes, potatoes and bananas/plantains. They are mainly consumed directly as boiled pieces or pounded in the form of smooth, not sticky, and stretchable dough. They are also stewed, steamed or fried. Cassava, the most widely grown RTB, is generally boiled, stewed or steamed in Eastern and Southern Africa, and in West and Central Africa is usually processed directly into derivative products, e.g. whole root fermentation through retting or heap fermentation; fermentation/dewatering of the mash. Biophysical and social knowledge presented in this issue help elaborate goals for both the processing unit operations (food scientist control) and variety traits (breeder control).     

Efficacy of acidic electrolyzed water for microbial decontamination of cucumbers and strawberries

An examination was made of the efficacy of acidic electrolyzed water (AcEW, 30 ppm free available chlorine), ozonated water (5 ppm ozone), and a sodium hypochlorite solution (NaOCl, 150 ppm free available chlorine) for use as potential sanitizers of cucumbers and strawberries. AcEW and NaOCl reduced the aerobic mesophiles naturally present on cucumbers within 10 min by 1.4 and 1.2 log CFU per cucumber, respectively. The reduction by ozonated water (0.7 log CFU per cucumber) was significantly less than that of AcEW or NaOCl (P < or = 0.05). Cucumbers washed in alkaline electrolyzed water for 5 min and then treated with AcEW for 5 min showed a reduction in aerobic mesophiles that was at least 2 log CFU per cucumber greater than that of other treatments (P < or = 0.05). This treatment was also effective in reducing levels of coliform bacteria and fungi associated with cucumbers. All treatments offered greater microbial reduction on the cucumber surface than in the cucumber homogenate. Aerobic mesophiles associated with strawberries were reduced by less than 1 log CFU per strawberry after each treatment. Coliform bacteria and fungi associated with strawberries were reduced by 1.0 to 1.5 log CFU per strawberry after each treatment. Microbial reduction was approximately 0.5 log CFU per strawberry greater on the strawberry surface than in the strawberry homogenate. However, neither treatment was able to completely inactivate or remove the microorganisms from the surface of the cucumber or strawberry.     

Superchilling of muscle foods: Potential alternative for chilling and freezing

Superchilling is an attractive technique for preservation of muscle foods which freezes part of the water and insulate the food products from temperature fluctuations thereby enhancing the shelf-life during storage, transportation and retailing. Superchilling process synergistically improves the product shelf-life when used in combination with vacuum or modified atmospheric packaging. The shelf-life of muscle foods was reported to be increased by 1.5 to 4.0 times relative to traditional chilling technique. Advantages of superchilling and its ability to maintain the freshness of muscle foods over freezing has been discussed and its potential for Industrial application is highlighted. Present review also unravel the mechanistic bases for ice-crystal formation during superchilling and measures to ameliorate the drip loss. The future challenges especially automation in superchilling process for large scale Industrial application is presented.     

Protein oxidation in muscle foods: a review

Protein oxidation in living tissues is known to play an essential role in the pathogenesis of relevant degenerative diseases, whereas the occurrence and impact of protein oxidation (Pox) in food systems have been ignored for decades. Currently, the increasing interest among food scientists in this topic has led to highlight the influence that Pox may have on meat quality and human nutrition. Recent studies have contributed to solid scientific knowledge regarding basic oxidation mechanisms, and in advanced methodologies to accurately assess Pox in food systems. Some of these studies have provided insight into the reactions involved in the oxidative modifications undergone by muscle proteins. Moreover, a variety of products derived from oxidized muscle proteins, including cross-links and carbonyls, have been identified. The impact of oxidation on protein functionality and on specific meat quality traits has also been addressed. Some other recent studies have shed light on the complex interaction mechanisms between myofibrillar proteins and certain redox-active compounds such as tocopherols and phenolic compounds. This paper is devoted to review the most relevant findings on the occurrence and consequences of Pox in muscle foods. The efficiency of different anti-oxidant strategies against the oxidation of muscle proteins is also reported.     

Application of microbial transglutaminase in meat foods: A review

Microbial transglutaminase (MTG) is an enzyme isolated from a variant of Streptomyces mobaraensis that forms covalent cross-links between protein molecules. Studies are being conducted since last two decades on utilization of MTG in meat foods to improve their characteristics, such as gelation, water-binding, emulsion stability, purge loss, cooking loss, etc. MTG is one of the important topics of interest in meat processing industry due to its advantages in practical utilization and commercial exploitation. This review will discuss about the overall applications of MTG in manipulating the functional properties of meat and meat products by means of various processes such as restructuring, value addition, etc.     

Recent advances in rapid and nondestructive determination of fat content and fatty acids composition of muscle foods

Conventional methods for determining fat content and fatty acids (FAs) composition are generally based on the solvent extraction and gas chromatography techniques, respectively, which are time consuming, laborious, destructive to samples and require use of hazard solvents. These disadvantages make them impossible for large-scale detection or being applied to the production line of meat factories. In this context, the great necessity of developing rapid and nondestructive techniques for fat and FAs analyses has been highlighted. Measurement techniques based on near-infrared spectroscopy, Raman spectroscopy, nuclear magnetic resonance and hyperspectral imaging have provided interesting and promising results for fat and FAs prediction in varieties of foods. Thus, the goal of this article is to give an overview of the current research progress in application of the four important techniques for fat and FAs analyses of muscle foods, which consist of pork, beef, lamb, chicken meat, fish and fish oil. The measurement techniques are described in terms of their working principles, features, and application advantages. Research advances for these techniques for specific food are summarized in detail and the factors influencing their modeling results are discussed. Perspectives on the current situation, future trends and challenges associated with the measurement techniques are also discussed.     

高效液相色谱法测定秘鲁鱿鱼肌肉中的有机酸

研究建立了高效液相色谱(HPLC)同时测定秘鲁鱿鱼肌肉中多种有机酸的方法。有机酸的分离采用Atlantis T3色谱柱(4.6 mm×150 mm,5μm),流动相为0.08 mol/L KH_2PO_4(pH 3.00),流速0.5 mL/min,柱温30℃,检测波长210 nm。丙酮酸、苹果酸、α-酮戊二酸、乳酸、乙酸、柠檬酸、富马酸、丁二酸、丙酸等9种有机酸均能够得到很好的分离,其相关系数均在0.999以上,相对标准偏差为0.03%~0.37%,有机酸的回收率为94.5%~105%。     

Dielectric barrier discharge plasma for microbial decontamination of dried laver: effects on physicochemical characteristics

Dielectric barrier discharge (DBD) plasma in atmospheric pressure air was used for microbial decontamination of thin sheets of dried laver, which are commonly used in kimbab preparation. Microbial contaminants namely aerobic bacteria, moulds and marine bacteria were found in sun‐dried laver sheets. DBD plasma was generated at an output voltage of 30 kV AC and a frequency of 30 kHz. Upon the plasma treatment of laver, 2.5‐log (99.68%), nearly 1.5‐log (96.84%) and above 1.0‐log (90%) unit reductions in viable counts of aerobic bacteria, marine bacteria and moulds were observed over a 10‐min period, respectively. The inactivation pattern fitted well to Singh–Heldman model or pseudo first‐order kinetics. Compared to control laver, no significant (P > 0.05) changes in the colour characteristics, total phenolic content and 2,2‐diphenyl‐1‐picrylhydrazyl radical scavenging activity were observed in plasma‐treated laver. Furthermore, DBD plasma‐treated laver sheets had exerted no negative impact on the sensory characteristics of kimbab and can extend the shelf life.     

国内外有机食品发展状况及我国有机食品发展问题和对策

一、国内外有机食品市场迅速发展 (一)国外有机食品市场需求状况 1.国外市场对有机食品需求旺盛 有机农业有近50年的发展历史,但在近十几年才得以迅速发展.这主要是由于消费者对健康和营养问题的日益关注,促进了国际市场对有机食品的需求日趋旺盛.