Effects of microwave-assisted hot water treatments designed against Mexican fruit fly (Anastrepha ludens) on grapefruit (Citrus paradisi) quality

BACKGROUNDHot water treatment (HWT) against Anastrepha ludens was developed achieving 48 degrees C in the core of grapefruits and holding it for 6min. After heating, the grapefruits were hydro-cooled and stored at 23 degrees C and analyzed for 16days. The effect of microwave-assisted HWT (MW-HWT) on grapefruit quality was analyzed and compared with the quality of fruits treated with HWT and control fruits (without treatment). The physicochemical properties and chemical composition of essential oil were analyzed. RESULTSMW-HWT was equivalent to HWT according to accumulated heat calculations, with the advantage of being shorter. Treatments significantly affected the weight, color, maturity index, juice content, firmness, titratable acidity, pH, and ascorbic acid content of the grapefruits (P<0.05), but had no effect on the total soluble solids (P>0.05). The major components identified in the essential oil were d-limonene and -myrcene, compounds responsible of the scent of the grapefruits. CONCLUSIONMW-HWT was shorter (130min) and had a lesser effect on the quality of the grapefruit when compared with fruits under HWT (188min duration). Thus, this treatment could be considered as an alternative method against the Mexican fruit fly in grapefruit. (c) 2017 Society of Chemical Industry