Immunological detection of moulds in food: relation between antigen production and growth

In a study of Notermans and Heuvelman (Int. J. Food Microbiol. (1985) 2, 247–258) an enzyme linked immunosorbent assay (ELISA) for detection of moulds was described. The ELISA used was based on detection of a heat stable, water extractable and genus specific antigen(s) produced by moulds. The results indicated the possibility of testing food products, whether or not heated, for mould contamination. In this study antigen(s) production by moulds was tested under different growth conditions. It was observed that production of antigen(s) was correlated with mycelium weight. Type of medium, including different fruit juices, did not affect the production of antigen(s). Also no differences between surface culturing and submerged culturing were observed. Both incubation temperature and water activity showed no significant effect on production of antigen(s). Within the genus Penicillium 43 out of 45 species tested produced identical antigen(s) in comparable quantities. The quantity of antigen(s), expressed as minimal detectable quantity of mould mycelium produced, varied from 6–108 ng/ml with an average of 32 ng/ml.     

腐败肉光谱在线检测及剔除系统研究

目的提供一种基于可见/近红外光谱技术的腐败猪肉在线检测及剔除系统,实现自动化检测。方法构建由同步模块、检测模块和剔除模块组成的检测系统。肉样随传送带运动,同步模块控制检测探头的调整,保证探头到肉样表面的距离,并使其与肉的传送同步进行;检测模块用于提取光谱并进行分析,得出是否腐败的结果;之后由剔除模块对腐败样本进行剔除。将光谱数据与理化值联立采用多元散射校正与主成分分析法进行光谱预处理,建立了基于Fisher算法的判别模型。结果系统信噪比100:1,在线判别准确率达到87.4%。结论该系统可以保证光谱检测的稳定性,能实现腐败肉的在线检测和剔除动作,为实际生产应用创造了条件。     

啤酒腐败菌耐乙酸乳杆菌种特异性检测体系的建立与应用

以耐乙酸乳杆菌的3个特异性基因为靶标,设计并优化了3对耐乙酸乳杆菌的特异性引物,建立了基于SYBR GREEN实时荧光定量PCR的耐乙酸乳杆菌定性定量检测的标准检测(standard operation procedure,SOP)方法。利用耐乙酸乳杆菌CN247的基因组DNA作为标准品绘制了标准曲线,实现了对耐乙酸乳杆菌的定量检测,耐乙酸乳杆菌的最低检测限可达100 CFU/m L,精度可达10 CFU/m L。大生产样品在培养基中富集培养48 h后即可满足检测的要求,检出率为100%,整个检测时间控制在3 d以内,满足了啤酒企业对出厂产品快速检测的质量控制要求。     

Invertase production of common storage moulds in food and feed grains as a possibility for rapid detection of Aspergillus flavus group and Aspergillus fumigatus

Invertase production of grain storage moulds was studied. Aspergillus spp. and Penicillium spp. were grown in a sucrose based liquid medium, at 37 degrees C. The A. flavus group (A. flavus, A. parasiticus, A. nomius, A. oryzae) and A. fumigatus showed a fast growth and intense invertase activity, while other Aspergillus spp. and Penicillium spp. grew slower and produced less invertase. The pattern of accumulated reducing sugar after 20 and 48 h of incubation was characteristic to the species studied. From inoculation studies the detection limit was calculated as: 1-10 conidia of A. flavus group and A. fumigatus, as compared to 10(3)-10(4) for the other species studied. The method may be recommended as a rapid test for the detection of A. flavus group and A. fumigatus in food and feed grains.     

Ecophysiology of ochratoxigenic Aspergillus ochraceus and Penicillium verrucosum isolates. Predictive models for fungal spoilage prevention - a review

Ochratoxin A (OTA) is a secondary metabolite produced by several species of Aspergillus and Penicillium; among them Aspergillus ochraceus and Penicillium verrucosum are two ochratoxigenic species capable of growing in different climates and thus contamination of food crops with OTA can occur worldwide. OTA can be found in a wide range of foods such as cereals, coffee, cocoa, spices, beer, wine, dried vine fruit, grapes and meat products. OTA is toxic to animals, it presents neurotoxic, immunotoxic and nephrotoxic effects. It has been implicated in a human kidney disorder known as Balkan Endemic Nephropathy. This review focuses on the ecophysiology of ochratoxin-producing Aspergillus ochraceus and Penicillium verrucosum, the effect of environmental factors on their germination, mycelial growth, and OTA production. Knowledge of environmental conditions required for sucessive stages of fungal development represent the first step towards preventing mycotoxin formation. Predictive models for different stages of fungal development are presented, which allow prediction of the time before spoilage as a function of the abiotic factors. Finally, the implications of these studies in management of barley, coffee and grapes are described. This can help to identify the critical control points in their production, storage and distribution processes.     

Rapid, specific, and sensitive detection of spoilage molds in orange juice using a real-time Taqman PCR assay

The outgrowth of spoilage organisms, including molds and yeasts, results in significant financial loss to the food industry and wastes natural resources. The objective of this study was to develop a rapid, specific, and sensitive real-time PCR method for detecting spoilage molds during screening of raw materials and final product quality control analysis. The 18S rRNA gene was used to develop PCR primers and probe. With this set of primers and probe, less than 1,000 mold cells per milliliter of orange juice (10 cells per reaction) were detected with the real-time PCR system within 6 to 7 h. No cross-reactivity was found with other common foodborne bacteria, yeasts, or food ingredients. This technique is significantly faster than current detection and identification procedures, which take from days to weeks.     

Media for the detection and enumeration of Bacillus cereus in foods: a review.

Bacillus cereus is an established cause of food poisoning in addition to being a troublesome and persistent contaminant, responsible for a variety of spoilage defects in processed foods and dairy products. A range of diagnostic and selective media has been developed to facilitate the detection and enumeration of B. cereus in routine surveillance situations and food poisoning investigations. These media are reviewed with respect to the selective and diagnostic systems they employ, their ability to recover and differentiate the target organism, and their advantages and limitations in particular applications.     

Application of molecular identification tools for Lactobacillus, with a focus on discrimination between closely related species: A review

Lactobacillus is among the most important GRAS food lactic acid bacteria, with nearly 140 species at present, mostly of industrial importance. Being part of the natural flora of a range of food products like raw milk, fermented dairy products, fruits, vegetables, meat products they also serve as starters for a number of fermented food products either to enhance the quality or to add health benefits. These groups of economically important species are often alike in phenotypic and physiological characteristics, probably due to their co-evolution in the same ecological niches; hence they are difficult to be differentiated. This demands advanced methods for their proper identification and characterization. With the advancement of molecular biology, a range of DNA-based molecular techniques has replaced the largely cumbersome phenotypic methods. This review summarizes the various molecular techniques available for detection and identification within the genus Lactobacillus, with special emphasis on the four groups of closely resembling species: L. casei group, L. acidophilus group, L. delbrueckii subspecies, and L. plantarum group. This review also provides insights into current trends for alternative molecular markers other than 16S rRNA to resolve the ambiguity within phylogenetically close species in the genus Lactobacillus.     

Potential uses and applications of treated wine waste: a review

Recently, there has been an upsurge in the exploitation of the waste materials generated by the wine industry. Wine waste is characterised by the presence of natural antioxidants much safer than synthetic antioxidants. Wine waste‐derived antioxidants have been recently used in the food industry. Moreover, wine waste can be potentially used as soil conditioner, as adsorbent for heavy metals, for fertiliser and for pullulan production. This review aims at presenting the most important and economically viable applications of treated wine waste.     

Mold spoilage of bread and its biopreservation: A review of current strategies for bread shelf life extension

Microbial spoilage of bread and the consequent waste problem causes large economic losses for both the bakery industry and the consumer. Furthermore the presence of mycotoxins due to fungal contamination in cereals and cereal products remains a significant issue. The use of conventional chemical preservatives has several drawbacks, necessitating the development of clean-label alternatives.

In this review, we describe current research aiming to extend the shelf life of bread through the use of more consumer friendly and ecologically sustainable preservation techniques as alternatives to chemical additives. Studies on the in situ-production/-expression of antifungal compounds are presented, with special attention given to recent developments over the past decade. Sourdough fermented with antifungal strains of lactic acid bacteria (LAB) is an area of increasing focus and serves as a high-potential biological ingredient to produce gluten-containing and gluten-free breads with improved nutritional value, quality and safety due to shelf-life extension, and is in-line with consumer's demands for more products containing less additives. Other alternative biopreservation techniques include the utilization of antifungal peptides, ethanol and plant extracts. These can be added to bread formulations or incorporated in antimicrobial films for active packaging (AP) of bread. This review outlines recent progress that has been made in the area of bread biopreservation and future perspectives in this important area.     

Melamine detection in milk using vibrational spectroscopy and chemometrics analysis: A review

Major advances in the field of chemometrics combined with the use of vibrational spectroscopy have proven essential for the identification and quantification of food contaminants. These techniques, which have guided the work of regulatory agencies overlooking the food industry, can be readily applied to monitor food processing, quality control, and quality assurance. These processes can ensure product authenticity with respect to variety, geographical origin, and presence or absence of contaminants. Food analysis by vibrational spectroscopy provides overall chemical composition of the tested food sample; therefore, it is widely considered to be a highly reliable and empirical fingerprints of that samples. In 2008, melamine adulteration of milk powder in China resulted in devastatingly adverse effects for both consumers and the overall Chinese economy at large. As a result, regulatory agencies have markedly increased their interest in using fast, reliable, and accurate methods for identifying food contaminants. In this article, we provide a detailed overview of the uses of vibrational spectroscopy methods and chemometrics for the detection and quantification of melamine in dairy products.     

Enhanced efficiency fertilisers: a review of formulation and nutrient release patterns

Fertilisers are one of the most important elements of modern agriculture. The application of fertilisers in agricultural practices has markedly increased the production of food, feed, fuel, fibre and other plant products. However, a significant portion of nutrients applied in the field is not taken up by plants and is lost through leaching, volatilisation, nitrification, or other means. Such a loss increases the cost of fertiliser and severely pollutes the environment. To alleviate these problems, enhanced efficiency fertilisers (EEFs) are produced and used in the form of controlled release fertilisers and nitrification/urease inhibitors. The application of biopolymers for coating in EEFs, tailoring the release pattern of nutrients to closely match the growth requirement of plants and development of realistic models to predict the release pattern of common nutrients have been the foci of fertiliser research. In this context, this paper intends to review relevant aspects of new developments in fertiliser production and use, agronomic, economic and environmental drives for enhanced efficiency fertilisers and their formulation process and the nutrient release behaviour. Application of biopolymers and complex coacervation technique for nutrient encapsulation is also explored as a promising technology to produce EEFs. © 2014 Society of Chemical Industry     

Peanut milk and peanut milk based products production: a review

Since the early 1950s, numerous reports have been published suggesting that peanut milk and peanut milk based products can be prepared in a wide variety of ways. Emphasis has shifted from preparing inexpensive milk like beverages, very nutritious but somewhat lacking consumers appeal, to using the peanut milk or peanut protein isolates as an animal milk extender without changing flavor, to develop more attractive fermented products, and to precipitate proteins from the milk in order to get a curd called "tofu," and to produce cheese analogs. Great attention has been paid to the improvement of the stability, sensory properties, and shelf-life of the milk, using physical and chemical treatments. Many efforts have been deployed for supplementing the products. Thanks to recent advances, the removal of aflatoxin from peanut milk can be achieved using Flavobacterium aurantiacum as a biodegradater. It has also found application as liquid coffee whitener. However, despite all these developments and publications, there is still a need for much more diversified studies in order to definitely overcome the stability, the nutty flavor, and sensory problems always encountered when producing peanut milk and some peanut milk based products.     

Nortriptyline for smoking cessation: a review.

This article reviews the efficacy of nortriptyline for smoking cessation based on a meta-analysis of the Cochrane Library. Six placebo-controlled trials have shown nortriptyline (75-100 mg) doubles quit rates (OR = 2.1). Between 4% and 12% of smokers dropped out because of adverse events, but no serious adverse events occurred. The efficacy of nortriptyline did not appear to be related to its antidepressant actions. Nortriptyline is an efficacious aid to smoking cessation with a magnitude of effect similar to that for bupropion and nicotine replacement therapies. Whether nortriptyline produces serious side effects at these doses in healthy, nondepressed smokers remains unclear because it has been tested in only 500 smokers. The finding that nortriptyline and bupropion are effective for smoking cessation but that selective serotonin-reuptake inhibitors are not suggests that dopaminergic or adrenergic, but not serotonergic, activity is important for cessation efficacy. Until further studies can verify a low incidence of significant adverse events, nortriptyline should be a second-line treatment for smoking cessation.     

A potentiometric electronic tongue for the discrimination of honey according to the botanical origin. Comparison with traditional methodologies: Physicochemical parameters and volatile profile

The effectiveness of a potentiometric electronic tongue, made of various metals and metallic compounds was evaluated for the differentiation of honey in three different states: raw, liquefied and pasteurized. Principal component analysis (PCA) and a neural network showed that potentiometric electrodes seem useful to classify honey by its botanical origin, though they do not seem capable of discrimination between applied thermal treatments. The same was observed in the samples for physicochemical parameters and volatile compounds analysed with PCA. Au, Cu and Ag electrodes were more decisive in the discrimination of honey. A remarkable correlation (PLS analysis) between the electronic tongue and the physicochemical parameters was found, the best results being for color Pfund (r² = 0.958), L^∗ (r² = 0.935) and diastase activity (r² = 0.926). The correlation with volatile compounds was much weaker, though this improved for specific characteristic compounds in each monofloral variety. Thus, this is a good starting point for the development of new systems focused on the honey sector.     

Potential of a simple HPLC-based approach for the identification of the spoilage status of minced beef stored at various temperatures and packaging systems

The shelf life of minced beef stored (i) aerobically, (ii) under modified atmosphere packaging (MAP), and (iii) under MAP with oregano essential oil (MAP/OEO) at 0, 5, 10, and 15 °C was investigated. The microbial association of meat and the temporal biochemical changes were monitored. Microbiological analyses, including total viable counts (TVC), Pseudomonas spp., Brochothrix thermosphacta, lactic acid bacteria, Enterobacteriaceae, and yeasts/moulds, were undertaken, in parallel with sensory assessment, pH measurement and HPLC analysis of the organic acid profiles. Spectral data collected by HPLC were subjected to statistical analysis, including principal component analysis (PCA) and factorial discriminant analysis (FDA). This revealed qualitative discrimination of the samples based on their spoilage status. Partial least squares regression (PLS-R) was used to evaluate quantitative predictions of TVC, Pseudomonas spp., Br. thermosphacta, lactic acid bacteria, Enterobacteriaceae, and yeasts/moulds. Overall, the HPLC analysis of organic acids, was found to be a potential method to evaluate the spoilage and microbial status of a meat sample regardless of the storage conditions. This could be a very useful tool for monitoring the quality of meat batches during transportation and storage in the meat food chain.