超声空化效应对食品品质影响研究进展

超声波是指频率高于20 kHz的机械波,其特点是频率高、波长短、功率大、穿透力强。作为一种非热加工技术,超声波目前已应用于食品加工的各个领域,如乳化、晶化、均质、剪切、清洗、水解、催陈、提取、杀菌、钝酶等。与传统的热加工技术相比,超声波具有设备简单、无化学残留,、处理时间短、耗能少、产热低、对食品品质影响少等优势。然而,近年来研究发现,由于超声波的"空化效应",高强度、长时间的超声处理也会使食品色泽、香气、风味、营养物质以及质地等方面发生改变,影响了产品的外观品质,降低了食品的食用价值。作者综述了目前国内外有关此方面的研究进展,以期为超声波技术在食品加工中的进一步应用提供理论基础和技术指导。

韩国食品用微生物菌种管理现状

韩国《食品卫生法》及相关《食品法典》将食品原料分为3类,即食品中可使用的原料、食品中限制性使用的原料及食品中禁止使用的原料。通过《食品公典》中相关目录及韩国食品医药品安全处建立的食品原材料数据库检索,截止到2015年7月,韩国在食品中可作为原料使用的微生物有69种(亚种/株),限制性使用的微生物有37种,禁止使用的微生物有17种,共计123种(亚种/株)。该文通过对韩国食品用微生物名单及相关法律法规进行收集、整理和解析,以期为我国微生物菌种的管理及其在食品中的应用提供参考。

A STUDY ON THE ADSORPTION OF LOW CONCENTRATION FREE ALKALI BY SUBACID RESIN

The absorption of free alkali at low concentration by subacid resin was traced with electric conductance method, the effect of temperature on the adsorption, the activation energy of adsorption (Ea) and interaction energy (U) was studied. The result showed that, the process of low concentration alkali adsorption by subacid resin was in accordance with mechanism of monomolecular layer absorption, in addition, with the increasing of temperature, the interaction energy between adsorbate and sorbent increase, so did the surface adsorption rate (k), and linear correlation existed between interaction energy (U) and temperature (T).

Global Solution for Preserving Citrus Fruit Using Natural Treatments

Different tests were carried out to assess the efficiency of replacing plant protection products used at the main application points in citrus fruit packinghouses with natural treatments. The efficiency of an aqueous treatment containing potassium sorbate was found to significantly reduce decaying in Marisol mandarins previously inoculated with Penicillium digitatum and Penicillium italicum. The same food preservative was used in conjunction with a fruit detergent and was applied on Washington Navel oranges and the reduction in the appearance of decaying was similar to that obtained using Guazatine. Finally, two different essential oils were tested. One was combined with a coating and the KS, whilst the other was applied as a fumigant. In the case of wax treatments, it was found that the combination of essential oil or KS with Imazalil at half the dose （0.1%） was equivalent to treatment with a higher dose of Imazalil （0.2%） thus making it possible to reduce the dose of plant protection products used without reducing decay control effectiveness. The treatment with a fumigant with essential oil has a level of efficiency similar to Imazalil against PI. These treatments can be considered a viable alternative to the use of plant protection products.

Fuzzy Models to Deal with Sensory Data in Food Industry

Sensory data are, due to the lack of an absolute reference, imprecise and uncertain data. Fuzzy logic can handle uncertainty and can be used in approximate reasoning. Automatic learning procedures allow to generate fuzzy reasoning rules from data including numerical and symbolic or sensory variables. We briefly present an induction method that was developed to extract qualitative knowledge from data samples. The induction process is run under interpretability constraints to ensure the fuzzy rules have a meaning for the human expert. We then study two applied problems in the food industry: sensory evaluation and process modeling.

The Possibilities of Bioenergy Production from Whey

The wastes and the by-products of food industrial technologies are suitable for bioenergy generating because of the high organic matter content. Anaerobic digestion is the eldest technology for waste stabilization and however by controlled decomposition a high value and marketable energy source can be produced. Whey is normally used as a component of dairy products or as an additive for food product. In our work we focused on another utilization method： biogas generating from membrane separated fractions i.e.： permeate and concentrate of whey. The effect of the pH, thermal, microwave pre-treatment and their combinations on the biogas yield were investigated. Our results showed that the applied pre-treatments had significant effect on biogas production. In consequence of the hydrolysis of large molecules the biodegradability of the pre-treated whey fractions was enhanced, therefore the biogas and methane production yield increased significantly.

Discovering Niche Market： Consumer Preferences and Willingness to Pay for Organic Pork

With the concern for environmental quality and food safety, organic food products are becoming more important in the global market. In recent years the organic food industry has been expanding and sales of organic products have been increasing. Abundant studies have been done focusing on organic fruits and vegetables which focused on the shortage of organic live stocks. In this paper we focus our attention on organic pork products. Using a sample of 400 Thais consumers, this study proposes the contingent valuation （CV） technique to measure the willingness of individuals to pay a price premium for organic pork in Thailand. In order to obtain the mean ＂willingness to pay＂ （WTP）, a bivariate probit model was applied to provide information about the crucial variables that affect the WTP. The study revealed that variables that better approximate WTP are based on the lifestyle and knowledge about organic foods rather than the usual socioeconomic factors. The mean WTP on the premium price for organic pork is approximately 34.30 Bath per kg. In order to access the market potential this study shows that the suitable attributes of organic pork which is consistent with consumer preferences are composed of modernized and environmental packaging with special product details. Marketing this product to the buyer it should be set at a reasonable price. Stimulating the market should be done by doing sales promotion and public relations on a regularly basis. In addition, organic pork should be available in any places and convenient for customers to buy.

Past, Present and Future of Military Food Technology

Food technology has been instrumental in ensuring that troops remain ＂fit to fight＂. Early food technologies produced flat bread, hard biscuits, cheese and salted meat, allowing Roman legionaries to carry rations for several days. Canning was invented in the late 18th century in response to the French Government＇s offer of a substantial reward to the person whose invention would allow troops to carry their food when marching long distances. World War II saw further advances in the form of stable and palatable canned meals, compressed cereal bars, candy-coated peanuts and other innovative foods in US combat rations. Two significant technology breakthroughs in the second half of the 20th century have altered the form of military rations. Freeze drying matured as an industrial technology, allowing the production of long-life, light-weight rations. Flexible packaging, based on plastic laminates, led to reduced weight and less waste disposal through the development of retort pouched meals （meals in flexible packaging that have undergone heat sterilization）, which have largely replaced metal cans in combat rations. Improvements in quality of military rations, particularly their organoleptic properties, are emerging through application of innovative technologies such as high-pressure thermal processing, pulsed electric field, and microwave assisted thermal sterilization. Research and development of ＂functional foods＂, such as those containing added essential fatty acids or probiotics offers the potential to provide combat rations that can further improve soldier health and performance.