The influence of different sugars and sugar alcohol, and cultivars in the osmotically dehydrated peach fruit. Analysis of mass transfer parameters and the variation in the organoleptic properties, bioactive and nutritive compounds, and pro-health properties in dried peaches

Peach is a great-taste fruit, source of nutrients and bioactive compounds. It is a seasonal fruit that cannot be stored for prolonged periods of time. To increase its consumption over the year, promote its intake as a snack, utilize it in the industry, process the overproduced peach and to add value to the fruit, osmotic dehydration (OD) followed by hot-air drying (OD+D) is a suitable process. Here, we compared the use of three different osmolytes (glucose, sorbitol or sucrose) and four peach cultivars (Flordaking, Goldprince, Elegant Lady and Dixiland) exposed to OD+D to study the effects on organoleptic, nutritional and nutraceutical properties of the peach. OD+D slices were compared against fresh fruit exclusively exposed to hot-air treatment (D). A moisture content of 17.5% was obtained in OD+D and D peaches. Moisture content, water loss, solute gain and colour depended on the cultivar. Higher metabolite and antioxidant capacity retention was observed for OD+D peach slices compared to D peaches, minimizing adverse changes such as carotenoid decrease typical of D and even enhancing some features such as tannin content. Moreover, OD+D improved the inhibition of protease, α-amylase and α-amyloglucosidase, key enzymes involved in inflammatory processes and hyperglycemia management. The dehydration processes modified the antimicrobial capacity of peach slices, with responses varying depending on the cultivar and obtaining better inhibitions than in D. Finally, although mineral composition was altered in OD+D due to leaking to the solution, the addition of calcium in the hyperosmotic solution resulted in calcium enriched dried peaches. Collectively, the results obtained reveal the influence of the cultivar on the properties of the dried fruit and highlight the benefits of the osmotic pretreatments prior to conventional drying.