Factors affecting quality and safety of fresh-cut produce.

The quality of fresh-cut fruit and vegetable products includes a combination of attributes, such as appearance, texture, and flavor, as well as nutritional and safety aspects that determine their value to the consumer. Nutritionally, fruit and vegetables represent a good source of vitamins, minerals, and dietary fiber, and fresh-cut produce satisfies consumer demand for freshly prepared, convenient, healthy food. However, fresh-cut produce deteriorates faster than corresponding intact produce, as a result of damage caused by minimal processing, which accelerates many physiological changes that lead to a reduction in produce quality and shelf-life. The symptoms of produce deterioration include discoloration, increased oxidative browning at cut surfaces, flaccidity as a result of loss of water, and decreased nutritional value. Damaged plant tissues also represent a better substrate for growth of microorganisms, including spoilage microorganisms and foodborne pathogens. The risk of pathogen contamination and growth is one of the main safety concerns associated with fresh-cut produce, as highlighted by the increasing number of produce-linked foodborne outbreaks in recent years. The pathogens of major concern in fresh-cut produce are Listeria monocytogenes, pathogenic Escherichia coli mainly O157:H7, and Salmonella spp. This article describes the quality of fresh-cut produce, factors affecting quality, and various techniques for evaluating quality. In addition, the microbiological safety of fresh-cut produce and factors affecting pathogen survival and growth on fresh-cut produce are discussed in detail.

[Gelatin-cystine, keratogenesis and structure of the hair]. / Gelatina-cistina, cheratogenesi e struttura pilifera.

It is known how noticeable modifications may be induced in the high sulphur content proteins of wool, by enrichment of the diet of sheep with cysteine or sulphur amino acids. It is also well known how the oral ingestion of gelatin significantly increases hair diameter and the degree of hardness of finger and toe nails. To the end of verifying the possible stimulating selective action performed by cystine and gelatin in the keratinization processes of the hairy structures, it was controlled: amino acids content in hair of normal rat after oral ingestion of a controlled quantity of gelatin-cystine added in the diet. The same experiments have been carried out on rats in which the condition of sufference of the hair was induced by means of a biotin-free diet. From the obtained data it seems that gelatin-cystine, added in the diet of normal or suffering rats, helps to modify the cysteine content of the sulphur-rich hair proteins (+ 50% abt.). The diet supplement bring about a considerable increasing of CYS (+ 35%) with a decreasing of GLY (- 15%).