Effect of chitosan coating on quality and nutritional value of fresh-cut and #8216;Rocha and #8217; pear

Abstract

One of the greatest barriers to the commercial marketing of fresh-cut fruit is limited shelf-life due to tissue softening and surface browning. Moreover, the development of microorganisms on the fruit surface can compromise the safety of the fresh-cut product. Edible coatings have been proposed as postharvest treatments to maintain quality and prolong shelf-life. The present work aims to evaluate the effect of chitosan coatings in physical, chemical, nutritional and microbiological characteristics of minimally processed 'Rocha' pear. Fruits were peeled, cut into slices and immersed in different quitosan solutions (0.7, 1, 1.5 e 2 g L-1). Treated samples were stored at 4ºC during 10 days. Physical and physicochemical analysis were performed, including moisture content, firmness, color, titratable acidity and total soluble solids. Nutritional analysis and microbiological evaluations of psychrophilic bacteria, molds and yeasts were also carried out. Chitosan coatings reduced water loss, maintained firmness, and reduced surface browning during storage. No negative effects were observed in the nutritional quality of treated pears. Chitosan coatings could be used to preserve quality and to extend shelflife of fresh-cut 'Rocha' pear.

Physicochemical Fingerprint of “Pera Rocha do Oeste”. A PDO Pear Native from Portugal

“…For the pulp, the a* and b* values ranged from −11.07 to 2.25 and 8.15 to 17.68, respectively. Similar color values for Rocha pear pulp were reported in other studies [ 27 , 28 ]. The a* and b* values of peel are considered good indicators to measure the influence of storage conditions [ 27 ], presenting values able to diagnose the storage of the fruits.…”

“…This index ranged from 37.24 to 141.11. The TSS and TA values observed in this work were similar to those reported for the “Pera Rocha do Oeste” pear [ 8 , 28 ], as well as those for Bartlett pear [ 30 ] and a Pyrus communis L. variety.…”

“…These values are characteristic of this cultivar, taking into account that the pear has a low vitamin C content [ 31 , 32 ]. The firmness of the “Pera Rocha do Oeste” pear under study had average values of 12.21 ± 2.51 N, which are similar to the literature [ 27 , 28 ]. The fruit flesh firmness decreases over time due to metabolic processes by the depolymerization of the cell wall polysaccharides, with a decrease more pronounced for pears undergoing 2 months of storage [ 33 ].…”

“…Considering the pH values ( Table 2 ), the “Pera Rocha do Oeste” pear can be classified as acidic, with a value of 4.81 ± 0.08, in accordance with the literature [ 28 ]. The total phenolic compounds, ranging between 39.26 and 93.10 mg gallic acid equivalents/100 g, are also similar to the literature [ 21 ].…”

Bazi Yeni̇lebi̇li̇r Kaplama Uygulamalarinin Yemeye Hazir Amasya Elmasinin Kali̇tesi̇ne Etki̇leri̇

“…There is no statistical difference between storage end values of CH and CHS coated samples (P >0.05). Sánchez et al (2015) reported that the decrease in hue angle showed a similar tendency in all treatments, and after 10 days, they observed only a slight difference between control and chitosan coated pear slices. In addition, similar effects of chitosan were observed in color preservation of fresh cut fruits such as strawberry, papaya, peach, pear, kiwi and mango (Du et al, 1997;Chien et al, 2007;Campaniello et al, 2008;Gonzalez-Aguilar et al, 2008).…”