EVALUATION OF GLUCOSE AND SUCROSE OSMOTIC DEHYDRATED AND HEAT-AIR-DRIED FLORDARKING PEACH SLICES DURING CONSERVATION

SALVAÑAL, LARA; GABILONDO, JULIETA; BUDDE, CLAUDIO OLAF; FRANCESCONI RAFAELA; GARITTA, L; PIERONI, VICTORIA; ANDRES, SILVINA C; GUGOLE OTTAVIANO FERNANDA; SOSA, M; LARA, MARÍA VALERIA; CORBINO, GRACIELA

Buenos Aires

Congreso; XVIII Congreso Argentino de ciencia y Tecnología de Alimentos. XVIII CyTAL® 2023; 2023

Prunus persica is a stone fruit source of multiple nutraceutical compounds. Fresh fruit has a short life; thus, manyprocessing procedures have been used to increase its consumption in alternative forms. One strategy is the use ofosmotic dehydration (OD) previous to conventional heat drying (D) since OD prevents browning, sugar caramelizingand degradation of bioactive compounds.Previously, we analyzed the effect on nutraceutical proprieties of an OD pre-treatment with glucose or sucrosesolutions applied to peach slices. Here, we studied the stability along storage time of these slices kept under 50 %relative humidity (RH) atmosphere during 55 days.For this purpose, Flordaking peach fruits were harvested at commercial maturity. Fruits were washed, cut in slices andimmersed in ascorbic acid solution to prevent browning. Slices were incubated at 40°C in a solution of sucrose orglucose (47° Brix) during 3 h under stirring. Next, slices were dried at 58°C during 4 h until 9.3-6.8 % relative watercontent and named as Suc+D or Glc+D, respectively. Slices were kept in a close jar where a supersaturated solution ofsodium bromide was also placed inside to achieve a 50 % RH atmosphere. The vessel was maintained in a closedchamber in the dark at 25˚ C for 55 days. Samples were taken immediately after processing (0) and after 15, 33, 41 and55 days. Fresh and dried weights were computed in each slice. Surface color was analyzed using a colorimeter. Toevaluate nutritional quality and bioactive compounds the following parameters were evaluated: total phenoliccompounds (TPC), flavonoids, carotenoids, ascorbic acid, total soluble protein, glucose, sucrose and sorbitol contentsand antioxidant activity by DPPH and ABTS methods, and expressed in a fresh or dry weight basis. A trained panelevaluated sensory texture of slices and a texturometer was also used.After 15 days of storage, water content of Suc+D and Glc+D slices raised until 25 % and kept constant during theperiod of analysis. While in Glc+D samples a decrease in carotenoids, total soluble proteins and antioxidant activitywas found with the days of storage, no statistical differences were found in most of the parameters measured along 55days. Similarly, in the case of Suc+D samples, the content of TPC, flavonoids, ascorbic acid, glucose, sucrose, sorbitolas well as the antioxidant activity remained unchanged during the period of conservation. Conversely, carotenoids andproteins decreased over time. Color analysis revealed that during storage the color of slices slightly got reddish and lessyellow than slices collected at day 0 when using sucrose or glucose for OD. Sensory descriptors and texture weresimilar in slices dehydrated with sucrose or glucose. In both cases, after 15 days firmness, oral breakdown and firmnessdecreased while texture, cohesiveness and crunchy perception increased.Collectively, our results show that an OD pretreatment with sucrose or glucose previous to conventional drying iseffective to preserve the nutraceutical and nutritional components of the dehydrated peach slices during at least 55 daysafter processing, making a suitable product for consumption.