Compositional,biochemical and textural changes during ripening of Tulum cheese made with different coagulants

In the present study, biochemical, chemical and texture changes in Tulum cheeses made using calf rennet and microbial rennets (Aspergillus niger protease and Rhizomucor miehei protease) were compared during ripening for up to 90 days. A total of 15 free fatty acids (FFAs) were detected in the cheese samples. The peroxide values (PV) of the cheeses increased significantly (P < 0.05) during ripening and the cheese made with calf rennet had the highest PV. Proteolysis in the cheeses increased as the ripening time increased. α_s1‐casein and β‐casein degradation was higher in cheeses manufactured with R. miehei protease. Cheeses made with calf rennet were significantly (P < 0.05) harder, more adhesive, more cohesive and more resilient than those made with microbial rennet.     

即食肉制品产业发展现状与市场前景

即食肉制品在加工、运输、贮藏和销售等环节极易污染细菌、酵母菌和霉菌,造成腐败变质并引发食源性疾病。大气压冷等离子体（Atmospheric cold plasma,ACP）是一种新型非热加工技术,具有杀菌效果好、处理温度低且对食品营养和感官影响小等优点,在食品杀菌保鲜领域具有广阔的应用前景。本文概述了ACP对微生物的杀灭作用和影响因素,介绍了ACP在即食肉制品杀菌保鲜中的应用研究进展,并探讨了ACP处理对即食肉制品中脂质、蛋白质、色泽及感官品质等指标的影响,以期为ACP在即食肉制品杀菌保鲜中的实际应用提供参考。     

Effect of reuterin produced by Lactobacillus reuteri on the surface of sausages to inhibit the growth of Listeria monocytogenes and Salmonella spp

Reuterin is a bacteriocin produced by some strains of Lactobacillus reuteri. The strain used in this study was isolated from raw milk from a dairy farm nearby Ankara. Beef sausage is a long years produced bratwurst style meat product in Turkey, as well as in some other countries in the Mediterranean region. Sausages are produced by raw meat; sometimes lactic starter cultures are added or spontaneous fermentation is employed. The production and storage conditions of the product promotes the growth of Listeria monocytogenes and Salmonella spp. Although nitrate is added as an antimicrobial substance against many pathogens, sometimes however nitrate application is not preventive enough on the surface because of the natural film around the sausages. Since most of the contaminations take place at post production steps, pathogenic growth is more effective on the surface of the sausages in refrigerated conditions. In this study, reuterin was applied to the surface of the sausages in order to prevent the growth of these two pathogens along with nitrate used as an additive in the product. Reuterin has inhibited the growth of L. monocytogenes considerably but not of Salmonella spp. on the surface of the sausages.     

Mycoflora of hazelnut (Corylus avellana L.) and aflatoxin content in hazelnut kernels artificially infected with Aspergillus parasiticus

In this research, 30 hazelnut samples were used to determine their internal mould populations and their aflatoxin contents. The results showed that Aspergillus was the most common genus in the experimental samples (96.6% of all samples). Thirty-one% of isolates were classified as Aspergillus flavus and none of the samples contained aflatoxins. In the second part of the experiment, the kernels were inoculated with conidia of Aspergillus parasiticus and incubated at three different humidified conditions and two different temperatures for 45 days. Aflatoxin contents of the samples kept in 98% relative humidity and at 28 degrees C were higher (904.6 micrograms/kg) than that of the other samples. On the other hand, no aflatoxin was detected in the control samples that were not inoculated but kept at the same conditions.     

Heavy metal bioaccumulation by cultivated Agaricus bisporus from artificially enriched substrates

Cultivated Agaricus bisporus possess the ability to bioaccumulate seven heavy metals (Pb, Cd, Hg, Fe, Cu, Mn, and Zn). The cultivated champignon mushroom A. bisporus was grown in soil composts of 16 different compositions. An edible mushroom, A. bisporus was also cultivated on humic compost artificially fortified with the seven heavy metals at five different concentrations (0.1 mg/kg, 0.5 mg/kg, 1.0 mg/kg, 3.0 mg/kg, and 10.0 mg/kg) and on control substrate (0 mg/kg) on a dry weight basis. The method of measuring bioaccumulation was flame atomic absorption spectrophotometry.     

Quality characteristics of strawberry genotypes at different maturation stages

The chemical composition and quality characteristics of nine promising hybrids and two varieties (“Osmanli” and “Camarosa”) of strawberries were evaluated for their quality attributes during ripening. Main soluble sugars, carboxylic acids, organic acids and ascorbic acid of experimental varieties were separated, identified and quantified using high-performance liquid chromatography with diode array spectroscopic and refractive index detections. Titratable acidity (TA), pH, total soluble solids (TSS) and TSS/TA ratio and their correlations were determined at ripe maturation stages for the 11 genotypes. Hybrid no. 11, a new strawberry cultivar, had desired fruit quality characteristics similar to Osmanli, which has a pleasant taste and is popular in Turkey.