Evaluation of cultivar susceptibility and storage periods towards aflatoxin B1 contamination on pistachio nuts
Aflatoxins (AFs) are potent sources of health risks to both humans and animals. Among them, AFB1 is the most hazardously toxic and the most frequent in various food commodities, including pistachio nuts. In this survey, the effect of the storage period on AFB1 accumulation on pistachio nuts was investigated. A total of 49 samples collected during the crop year of 2005 from the most cultivated pistachio cultivars in Tunisia were rapidly screened by enzyme-linked immunosorbent assay (ELISA) combined with an immunoaffinity step. The obtained results showed that the contamination of pistachio nuts has occurred clearly after two years of storage for all the tested cultivars except the case of Mateur variety and Thyna ecotypes. In this study, the cultivar Mateur was found to be the most susceptible cultivar to contamination by AFB1. After 4 years of storage, the average contamination levels in nut samples ranged from 2.7 ± 0.3 to 12.7 ± 2.2 µg/kg for AFB1, according to the cultivar. These levels exceeded the maximum permitted limit of 2 µg/kg set by the European Commission in nuts.
The effects of a pressure extraction system on quality the parameters of different virgin pistachio ( Pistacia vera L. var. Larnaka ) oils
Pistachios are a good source for oil extraction as they are rich in unsaturated fatty acids and other bioactive components like polyphenols and phenolic compounds. The yield and quality parameters of the oil extracted from four batches of pistachios with different sizes were analyzed. Two different pressure systems (screw press and hydraulic press) were used for oil extraction. The yield was higher when the screw press was used, especially when the highest quality pistachios (larger pistachios) were used to extract the oil (40 ± 2.12%). With the hydraulic press, the yield was around 30% for all pistachio types. The color of the oils extracted with the screw press was darker than the oil extracted with the hydraulic press in all types of pistachios used. No significant differences were found in the acidity, K 270 , and K 232 values when high quality pistachios were used. When lower quality pistachios (smaller pistachios) were used, the values of these three parameters increased in comparison with larger pistachios. On the other hand, oil samples from lower quality pistachios obtained by the screw press showed the highest values. The oxidative stability was higher in the samples of oil from high quality pistachios, with no differences in regard to the extraction system. When lower quality pistachios were used, the oxidative stability was significantly lower.
The status of FAO and codex alimentarius developments on vegetable proteins
The FAO is interested in increasing world protein supplies both by advising and assisting developing countries to increase their production of staple foods and by encouraging the development of technology to produce protein concentrates both from vegetable and animal sources to supplement diets which are low in protein content. Recent revisions of the amount of protein required in the diet in relation to total per capita energy requirements and the difficulties encountered in introducing novel foods into established dietary patterns has led FAO to concentrate on increased agricultural productions in developing countries as the primary means of combatting malnutrition. In the meantime, in North America and Europe, advances in the technology of processing vegetable proteins has given highly acceptable products simulating meats which are being used as meat extenders and meat analogues. The consequent increase in vegetable protein production has revealed a need for international, agreement on standardization, and it has been agreed that this will be undertaken by the Joint FAO/WHO Food Standards’ Programme. The program operates chiefly through the Codex Alimentarius, Commission, an international governmental body, the purpose of which is to protect consumers against health hazard in food and against fraud. The Commission, which has 116 member governments, controls an intensive program of work covering the composition, labeling, additives, contaminants, pesticide residues, hygiene, sampling and analysis aspects of foods and has established a procedure which allows member governments ample opportunity to reach agreement on food standards and to accept them for incorporation into national legislation. The Codex Commission, at its 12th session, decided to establish a Committee on Vegetable Proteins with the following terms of references: “to elaborate definitions and world-wide standards for vegetable protein products deriving from soybeams, cottonseed, groundnuts, cereals and from other vegetable sources as they come into use for human consumption, and to elaborate guidelines on utilization of such vegetable protein products in the food supply system, on nutritional requirements and safety on labeling and on other aspects as may seem appropriate.” The question of which country will host the Committee is still under discussion.