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Orange Juices Enriched With Chitosan: Optimisation For Extending The Shelf-Life, Catherine Barry-Ryan, Ana Belen Martin-Diana, Daniel Rico, J. Barat
Orange Juices Enriched With Chitosan: Optimisation For Extending The Shelf-Life, Catherine Barry-Ryan, Ana Belen Martin-Diana, Daniel Rico, J. Barat
Articles
Optimisation of the incorporation of chitosan in orange juice was accomplished by the evaluation of quality and nutritional markers. Response surface methodology was applied to obtain quadratic and second degree response surface model equations. The analyses showed that increases in chitosan concentration extended the quality of the orange juice significantly (p < 0.05), reducing enzymatic and non-enzymatic browning and controlling the spoilage during the storage time; however, concentrations N 1 g L− 1 produced a significant (p < 0.05) reduction in the concentrations of ascorbic acid and carotenoids associated with the positive charge of chitosan and its ability to flocculate and coagulate negatively charged substances. Also, concentrations N 1 g L− 1 were scored as unacceptable for the sensory panel due to an increase in bitterness. The study recommends the use of chitosan at concentrations up to 1 g L− 1 to extend quality and preserve ascorbic acid and carotenoids during storage time of fresh orange juice, thus avoiding the use of standard thermal treatments which produces a negative impact on the nutritional value. Industrial relevance: One of the major problems of fresh orange juice is its limited shelf-life. Spoilage and quick degradation of vitamins are two of the most important causes of quality loss during the shelf-life of this product. Moreover, the U. S. Food and Drug Administration issued a warning to consumers against drinking unpasteurised orange juice products because of the potential contamination with Salmonella typhimurium and its association with an outbreak of human disease caused by this organism [FDA issues nationwide health alert on Orchid Island unpasteurised orange juice. Products Recalls, Market Withdrawals and Safety Alerts.]. The main objective of this study was the study of chitosan as a natural preservative for extending the shelf-life of orange juice and as an alternative to pasteurisation.
Inactivation Of Escherichia Coli In Orange Juice Using Ozone, Sonal Patil, Paula Bourke, Jesus Maria Frias, Brijesh Tiwari, Patrick Cullen
Inactivation Of Escherichia Coli In Orange Juice Using Ozone, Sonal Patil, Paula Bourke, Jesus Maria Frias, Brijesh Tiwari, Patrick Cullen
Articles
This research investigated the efficacy of gaseous ozone for the inactivation of Escherichia coli ATCC 25922 and NCTC 12900 strains in orange juice. Orange juice inoculated with E. coli (106 CFU mL-1) as a challenge microorganism was treated with ozone at 75-78µg mL-1 for different time periods (0-18 min). The efficacy of ozone for inactivation of both strains of E. coli was evaluated as a function of different juice types: model orange juice, fresh unfiltered juice, juice without pulp, and juice filtered through 500mm or 1mm sieves. Fast inactivation rates for total reduction of E. coli …