Orange juices enriched with chitosan: Optimisation for extending the shelf-life

Abstract

Ab s t r a c tOptimisation 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 extende d the quality of the orange juice significantly (p b 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 N 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, concentration s 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 asco ic acid rb and carotenoids during storage time of fresh orange juice, thus avoidi g the use of standard thermal n 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 again t s 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.

Evaluation of polypropylene/montmorillonite nanocomposites as food packaging material

“…AA is usually degraded by the oxidative process, which is stimulated in the presence of light, oxygen, heat, peroxides, and enzymes [39]. In contrast to our findings, the overall AA reduction in juices has been associated to the non-barrier properties of packaging against oxygen [38] and the extent of storage time [40].…”

Apple juices processed by high hydrostatic pressure: Interaction between chitosan application and quality drift

“…124-133 (green/yellow), suggesting the endorsement of electrostatic interactions, as in acid solution charge neutralization can be achieved just with high chitosan contents (Jiang et al, 2011). According with previous reports Martín-Diana et al, 2009), our data further suggest that among the juice samples treated with chitosan (T1-4), the inhibition of the enzymatic browning triggered by polyphenoloxidases (Weemaes et al, 1998;Rocha et al, 1999) implicates two hydroxyl groups and a partially acetylated amino group (Wenjun et al, 2002), through blocking of the binding of the enzyme to prevent the use of oxygen.…”

“…Yet, considering public health implications of sulfite in food products, chitosan can replace this chemical entity, as an antioxidant agent (Shahidi et al, 1999), mostly due to its positive ionic charge that can break lipids and acids. As an accumulating effect, this polymer can still change the gelling, stabilizing and thickening properties of food products (Martín-Diana et al, 2009).…”

“…Essentially has glucosamine, amino-2-β-2deoxi D-glucose, results from the alkaline deacetylation of chitin (Martín-Diana et al, 2009), being its solubility directly related to the amount of protonated amino groups (Pinto, 2005), whereas the antioxidant properties varies with its molecular weight (Rocha et al, 1999;Wenjun et al, 2002;No et al, 2007).…”

Evaluation of nanocomposite packaging containing Ag and ZnO on shelf life of fresh orange juice

“…According to Table 1, a significant decrease is observed in the ascorbic acid content of all the experimental packages during storage at 4°C while the browning index increased significantly in all the test packages. This overall AA reduction might be due to the nonbarrier properties of packaging against oxygen (Fellers, 1988;Sadler et al, 1992) and the duration of storage time (Martín-Diana, Rico, Barat, & Barry-Ryan, 2009). Based on the same table, loss of ascorbic acid and development of brown pigments are significantly higher in LDPE + 5% P105 than in other packages while the rates for these changes decrease with decreasing nanosilver concentration in LDPE + 1.5% P105.…”