Postharvest sweet cherry quality and safety maintenance by Aloe vera treatment: A new edible coating
D. Mart´nez-Romero a , N. Alburquerque b , J.M. Valverde a , ı F. Guill´ n a , S. Castillo a , D. Valero a , M. Serrano c,∗ e
Department of Food Technology, EPSO, University Miguel Hern´ ndez, Ctra. Beniel km. 3,2, 03312 Orihuela,Alicante, Spain a b Department Fruit Growing, IMIDA, C. Mayor s/n, 30150 La Alberca, Murcia, Spain c Department of Applied Biology, EPSO, University Miguel Hern´ ndez, Ctra. Beniel km. 3,2, 03312 Orihuela, Alicante, Spain a Received 16 May 2005; accepted 8 September 2005
Abstract A novel edible coating based on Aloe vera gel, accordingly to our developed patent (SP Patent Filed P200302937), has beenused as postharvest treatment to maintain sweet cherry quality and safety. During cold storage, uncoated fruit showed increases in respiration rate, rapid weight loss and colour changes, accelerated softening and ripening, stem browning and increased microbial populations, these processes being more intense during the shelf life periods. On the contrary, sweet cherry treated with A. vera gelsigniﬁcantly delayed the above parameters related to postharvest quality losses, and storability could be extended. The sensory analyses revealed beneﬁcial effects in terms of delaying stem browning and dehydration, maintenance of fruit visual aspect without any detrimental effect on taste, aroma or ﬂavours. As far as we aware, this is the ﬁrst time A. vera gel is used as an edible coating in fruit,which would be an innovative and interesting means for commercial application and as alternative of the use of postharvest chemical treatments. © 2005 Elsevier B.V. All rights reserved.
Keywords: Aloe vera; Colour; Firmness; Ripening; Sensory analyses
1. Introduction Sweet cherry is one of the most appreciated fruit by consumers since it is an early season fruit and has an excellent quality.The main quality indices are skin colour, which is related to fruit ripening and affected by anthocyanin concentration (Serrano et al., 2005a), and total soluble solids-total acidity ratio (TSS/TA) at harvest. Both parameters, together with the absence of stem browning determine consumer acceptance (Crisosto et al., 2003). TSS ranges between 11 and 25◦ Brix depending on cultivar and is mainly due toglucose and fructose and less to the presence of sucrose and sorbitol. TA depends also on cultivar, with levels of 0.4–1.5%, the main organic acid being malic acid (Esti et al., 2002; Bernalte et al., 2003). Fruit ﬁrmness is also an important quality attribute and is directly related to enhancement of storability potential
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and induction of greater resistance to decay and mechanical damage (Barret and Gonz´ lez, 1994). a Sweet cherry fruit deteriorate rapidly after harvest and in some cases do not reach consumers at optical quality after transport and marketing. The main causes of sweet cherry deterioration are weight loss, colour changes, softening, surface pitting,stem browning and loss of acidity, while low variations occur in TSS (Bernalte et al., 2003). Finally, special care is needed with the occurrence of decay, which is mainly due to species of the genera Penicillium, Botrytis and Monilia (Venturini et al., 2002). This fungal spoilage can cause great economic losses, although the occurrence of rots and their inﬂuence on sweet cherry quality have beenreported to be dependent on cultivar and ripening stage at harvest (Esti et al., 2002; Kappel et al., 2002). Several preand postharvest technologies have been used to control decay, but the postharvest use of chemicals as fungicides is restricted in most countries and consumers demand agricultural commodities without pesticide residues (Wilcock et al., 2004).
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