A field survey of pistachio (Pistacia vera) nut production and storage in Turkey with particular reference to aflatoxin contamination.

A field study of soils and pistachio nuts in three major pistachio-growing areas of Turkey has been undertaken. The predominant soil fungus isolated from all three areas was Aspergillus niger; isolates of Fusarium, Trichoderma, Mucor and Rhizopus species were also common. A flavus and A. ochraceus and related organisms were isolated only from the plateau of Gaziantep. The dominant external mycoflora of the immature nuts from all sites consisted of A. niger, A. flavus and Penicillium spp. There was no evidence for fungal contamination of immature endosperms nor of freshly dehulled nuts, but stored dehulled nuts and dust samples taken from ware-houses were extensively contaminated with A. flavus, A. niger and A. ochraceus. Of 43 A. flavus isolates tested, 20 produced aflatoxins on laboratory media or on rice; all 11 isolates of A. ochraceus tested produced ochratoxin A on laboratory media. The results obtained are discussed in relation to agricultural and marketing practices for Turkish pistachio nuts.     

The use of caproic acid to prevent aerobic deterioration of silages after opening,with special reference to the amounts and time of application

The effectiveness of caproic acid (hexanoic acid) addition to silages prepared from Italian ryegrass or cocksfoot (dry matter 16.3–34.5%) in preventing aerobic deterioration after opening was investigated in five experiments with varying amounts and times of application. Silages prepared in PVC bag silos were transferred to expanded polystyrene containers and left in a room at 25°C for 7 days with access to air. Aerobic deterioration was judged by rise in temperature, increase in pH and changes in the counts of yeasts and moulds. A low dry matter silage containing a fairly large amount of butyric acid was stable, and another low dry matter silage was relatively stable. Silages made from wilted grass deteriorated. Application of 50 mmol/kg grass at ensiling prevented deterioration in all cases. The effect was also observed with 50 mmol addition at opening, 10 mmol at ensiling and 10 mmol at opening in that order.     

果粒饮料储液搅拌缸的设计与参数优化

设计一种果粒饮料储液搅拌缸,对储液搅拌缸缸体、搅拌桨结构进行设计,并给定其各项参数。采用正交试验法与FLUENT相结合进行数值模拟,确定搅拌桨安装高度、搅拌桨叶片直径、搅拌桨的旋转速度等因素对搅拌过程的影响程度,并对储液搅拌缸进行参数优化,得到最佳参数解。结果表明:影响储液搅拌缸搅拌稳定后果粒浓度幅值的因素主次顺序为:桨直径、搅拌速度、下层桨高度。研究成果可为后续的果粒饮料一体化灌装机的设计提供参考。     

The determination of polychlorinated biphenyl residues: a review with special reference to foods

The determination of polychlorinated biphenyls presents several unique analytical problems, not least of which is the need to identify and quantify 209 possible analytes. Moreover, congener-specific analysis is essential because of structure-activity effects on toxicity and environmental stability. Although significant advances have been achieved in identification/quantification procedures with the aid of highly efficient, inert open tubular chromatography columns and coupled GC-MS, sampling and extraction procedures have not developed to the same extent. The primary focus of this review is the determination of polychlorinated biphenyls in foods. However, the problems of separation and identification overshadow the importance of the sample matrix, and relevant data from other areas of analysis are quoted.     

Grain storage systems and effects of moisture,temperature and time on grain quality - A review

Global grain production has been increasing every year, which highlights the need for investment, maintenance, and effective management in warehouses. Warehousing is a major bottleneck as it influences the possibility of negotiating for better market prices. In order for profitability to be increased, assurance of product quality for the consumer is necessary. Hence, there is a need for standardization of scientific research and the production chain in this field. The purpose of this bibliographic review is to describe the existing storage systems for grains, steps to be taken for care, and the main studies carried out in this field, to guarantee grains of good quality. The maintenance of the characteristics of the grains after harvest, is essential to guarantee grains of good quality to consumers. However, there are still deficiencies in the field of grain storage, and features of the different systems and conditions to be adopted for each of them are provided in this review.     

National estimates of the body composition of British cattle, sheep and pigs with special reference to trends in fatness. A review

National carcass classification records for cattle, sheep and pigs were used as a basis for estimating the body composition of British livestock slaughter populations. The tissue percentages of carcasses in each classification fatness range were estimated from regression equations constructed using data from breed comparison trials and other sources. The lipid and protein contents of the tissues were then estimated using regression equations from body composition studies. The mean carcass composition, and lean and fat production from current populations (1984) were compared with those of ten years ago. There has been an important increase of 20 kg (8%) in carcass weight for beef but no change in carcass composition. The average beef carcass in 1984 was estimated to contain 23% lipid (inclusive of lipid in perinephric and retroperitoneal fat). The weight of sheep carcasses has fallen by 0·6 kg (3 1 2% ) since 1977 without any appreciable change in carcass composition. The average sheep carcass in 1984 was estimated to contain 24% lipid. The lipid content of the average pig carcass was estimated to have fallen significantly from 27% in 1975 to 22% in 1984, with a small increase in carcass weight.     

A novel and simple approach for assessing the freshness of hazelnuts

Visual inspection and sensory analysis are the only suitable ways to assess the quality of hazelnuts under routine conditions. To obtain a more objective parameter for the freshness, a fast and easy-to-use method was developed. It is based on the well-known test for the germination capacity of seeds where their vitality is determined by use of 2,3,5-triphenyltetrazolium chloride (TTC) which is reduced by flavo enzymes to 1,3,5-triphenylformazane, which appears red. For the determination, 100 hazelnut halves were embedded in TTC containing methyl cellulose gel on a glass plate and kept at 35 °C in the dark. After 6 h, the cut planes of viable nuts were stained red, the cut planes of rotten nuts were yellow or brown, and the colour of dead or mould-infected nuts remained unchanged. The colour pattern was examined either visually by counting the coloured halves or with computer support using image editing software. The ratio of the sum of coloured areas to the total area of the hazelnut cut planes gave a measure of the average degree of viability ("vitality index"). The analysis of several samples of hazelnuts of well-defined age and storage conditions confirmed the efficiency of the method.     

A micro-method for the estimation of oil content and fatty acid composition in seeds with special reference to cyclopropenoic acids

A micro-method is described for the routine estimation of oil content and fatty acid composition in seeds containing cyclopropenoic fatty acids (CPEFA) by determination of the total and component long-chain fatty acids. The oil was transmethylated without prior extraction using 1.17% sodium methoxide in methanol at 80°C for 45 min. The resultant fatty acid methyl esters were separated and measured by gas-liquid chromatography using a glass capillary column coated with Carbowax 20 M at 170°C. The method was shown to be applicable to a wide range of seeds including cottonseed (Gossypium hirsutum), kapok (Ceiba pentandra), paka (Urena lobata), baobab (Adansonia grandidieri and A. suarezensis). Individual seeds can be used with this method which needs only 50 to 150 mg for analysis. Results obtained with this micro-method were reproducible and good recoveries of oil and individual fatty acids were observed. The micro-method was compared for the determination of CPEFA (malvalic plus sterculic acids) to the nuclear magnetic resonance quantitation and gas-liquid chromography after derivatisation of CPEFA in more stable compounds.     

储藏条件对油莎豆及其油脂品质的影响

为了探究不同储藏条件对油莎豆及其油脂品质的影响,将油莎豆在不同的温度(15、35℃)和湿度(11%、97%)下储藏40 d,测定油莎豆的含水量和含油量,以及油莎豆油的脂肪酸组成、维生素E含量和傅里叶红外光谱特征变化。结果表明：高湿(97%)条件下油莎豆含水量显著增加;低温低湿(15℃、11%)条件下油莎豆的含油量最高,为28.73%,高温高湿(35℃、97%)条件下最低,为26.82%;不同储藏条件下油莎豆油的脂肪酸组成没有显著变化,但高温和低湿储藏条件导致油莎豆油中饱和脂肪酸和多不饱和脂肪酸含量升高,单不饱和脂肪酸含量降低;油莎豆油中维生素E含量为171.34～183.80 mg/kg,主要成分为α-生育酚(117.70～126.12 mg/kg)和β-生育酚(40.55～45.38 mg/kg),相对于其他条件,高温低湿(35℃、11%)条件下油莎豆油中维生素E损失最严重;在试验考察范围内,储藏条件未对油莎豆油的官能团和结构产生明显影响。综上,选择适当的储藏条件有利于油莎豆的安全储藏。     

Development of effective drying strategy with a combination of radio frequency (RF) and convective hot-air drying for inshell hazelnuts and enhancement of nut quality

Drying characteristics of combined radio frequency (RF) and hot-air (HA) were investigated for inshell hazelnuts (Corylus avellana L.), which have air-gap between kernel and shell (shell, kernel, and air-gap between them). Inshell hazelnuts were subjected to HA, HA followed by RF (HAFRF), RF followed by HA (RFHA), and HA assisted RF (HARF) drying (simultaneous process). Fiber optic sensors were used to monitor temperature profiles for both hazelnut kernels and shells at three representative locations (center, edge, and corner) in a tray in 6-kW 27.12-MHz RF system with or without HA (~75 °C). RF heating resulted in higher kernel temperature than shell and was effective to remove kernel moisture. When RF heating was applied during or before HA drying, energy efficiency, drying efficacy, and nut quality were enhanced. This study provided a better understanding of drying characteristics of combined RF and HA process and suggested efficient RF-implemented drying strategies for inshell hazelnuts.     

A review of alternatives to organophosphorus compounds for the control of storage mites

This literature review aims to identify potential alternatives to the use of organophosphorus pesticides for the control of mite pests in stored commodities. Substances including insect growth regulators, inert dusts, botanicals, pyrethroids and other novel materials are discussed with emphasis on their efficacy against important storage mite pests. Their modes of action, together with the advantages and disadvantages of their use within a storage environment, are reviewed including cited efficacy against storage insects. Inert dusts meet criteria required for a product to be an effective replacement for OPs, and may offer the greatest potential. The future of any alternative lies in its ability to be incorporated into an integrated pest management programme.     

Permeability barrier of the gram-negative bacterial outer membrane with special reference to nisin

The effect of nisin pretreatment on organic acid-induced permeability increase in strains of Escherichia coli, Pseudomonas aeruginosa, P. marginalis, and Salmonella enterica sv. Typhimurium was investigated, using assays based on the uptake of a fluorescent dye 1-N-phenylnaphthylamine (NPN) and on the bacterial susceptibility to detergent-induced bacteriolysis. The outer membrane of bacteria which had been pretreated with nisin was shown to be less stable against 1 mM EDTA, as indicated by their significantly higher NPN uptake levels as compared to untreated bacteria. Upon challenge with a tenfold lower concentration of EDTA (0.1 mM) some nisin-treated strains (Typhimurium, P. marginalis) exhibited, however, NPN uptake levels which were lower than those seen in control bacteria, suggesting that nisin had stabilized their outer membrane. Nisin pretreatment also decreased the NPN uptake induced by citric or lactic acid or both in E. coli, P. marginalis, and Typhimurium, whereas in P. aeruginosa the pretreatment resulted in increased NPN uptake in response to citric and lactic acid. These results suggest that, with the exception of P. aeruginosa, nisin could protect bacteria from the outer membrane-disrupting effect caused by the acids. P. aeruginosa was, however, shown to be protected against bacteriolysis induced by the detergents sodium dodecylsulfate and Triton X-100. With a pair of isogenic mutants of Typhimurium differing in their cell surface charge it was shown that the NPN uptake response to 1 mM EDTA of the abnormally cationic strain was not significantly affected by nisin, whereas in the normal anionic strain nisin strongly strengthened the uptake. Our hypothesis based on these findings is that the normally anionic cell surface of Gram-negative bacteria has a tendency to bind the cationic nisin. The binding of nisin to the surface does not proceed to the cytoplasmic membrane, but in the outer membrane the bound nisin actually stabilizes its structure through electrostatic interactions. With the exception of EDTA, the organic acids at pH 4 did not cause leakage of cell contents from Typhimurium, indicating that these acids do not permeabilize the outer membrane to an extent required for cytoplasmic pore formation by nisin.     

Creep of cement bonded particleboard with special reference to the influence of humidity and temperature

This paper describes an investigation on creep behaviour of cement bonded particleboards loaded in bending, with special reference to the influence of humidity and temperature (tropical and temperate climatic conditions).