Survival of Escherichia coli O157:H7 during the manufacture and ripening of Cacioricotta goat cheese.
The aim of this study was to assess the growth and survival of Escherichia coli O157:H7 during the manufacturing and ripening of Cacioricotta goat cheese. Goat milk was artificially contaminated with E. coli O157:H7 and the bacterial load was monitored from production up to 90 days of ripening. Goat milk was inoculated with 102 cfu ml-1 of E. coli O157:H7 and the bacterial count of the curd at time zero was 2.31 log10 cfu g-1. During the first day of ripening, the bacterial load has increased to 5.73 log10 cfu g-1 to more than 6.20 log10 cfu g-1 during the first week. The bacterial load remained constant up to 28 days and then slightly decreased until the end of ripening, with values of aw and pH of 0.88 and 5.41 respectively. The results of this study highlighted that E. coli O157:H7 is able to survive the manufacturing process and they suggest that the 90-day period of ripening alone is insufficient to remove E. coli O157:H7 in contaminated Cacioricotta goat cheese. Moreover, these results support the assumption that the presence of a low contamination of milk with E. coli O157:H7 could represent a potential source of infection and a threat to consumers.
A synergistic mixture of Origanum vulgare L. and Rosmarinus officinalis L. essential oils to preserve overall quality and control Escherichia coli O157:H7 in fresh cheese during storage
Abstract The effects of Origanum vulgare L. (OVEO) and Rosmarinus officinalis L. (ROEO) essential oils in combination on the counts of a mesophilic starter co-culture and Escherichia coli O157:H7 in cheese were determined during 21 days of refrigerated storage. Prevalent OVEO and ROEO terpenes, as well as the physicochemical and sensory aspects of cheese, were also determined. OVEO (0.03 μL/g) and ROEO (1.32 μL/g) did not decreased the counts of Lactococcus spp. while caused a decrease of approximately 3.0 log CFU/g in counts of E. coli O157:H7 in the earlier 12 days of storage. Terpenes of OVEO and/or ROEO decreased during storage in cheese and showed a correlation with decreases in E. coli O157:H7 counts. Eucalyptol, camphor, α-pinene and camphene were detected until 18 days of storage, and only eucalyptol, camphor and α-pinene were detected until 21 days of storage. OVEO and ROEO did not affect the physicochemical parameters and characterized the cheese by the refreshing aroma, mint-like flavor and softness. These results show the prevalent terpenes of OVEO and ROEO in fresh cheese during refrigerated storage and suggest their incorporation during manufacture as a strategy to preserve this product, with particular effects on the survival of E. coli O157: H7.
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.