Nutritional, Sensory, and Physicochemical Properties of Vitamin E- and Mineral-fortified Fresh-cut Apples by Use of Vacuum Impregnation

Abstract

This study evaluated fresh-cut apples (Fuji) fortified with vitamin E and minerals by use of the vacuum impregnation (VI) technique. A 20% diluted high fructose corn syrup (HFCS) or 1% calcium caseinate (CC) aqueous solution were used as VI solutions, and 0.4% a-tocopherol acetate, 7.5% Gluconal Cal° (GC), and 0.04% zinc lactate (ZL) were incorporated into the VI solutions for the purpose of nutritional fortification. For VI treatment, fresh-cut apples were immersed in VI solutions subjected to vacuum at 100 mm Hg for 15 min following atmospheric restoration for 30 min. Apples were packed in the polyvinyl chloride (PVC) hinged clear containers and stored at 2 °C and 88% RH up to 3 wk. Nutritional contents, consumer sensory acceptability, microbial population, color, and firmness of the apples were evaluated during cold storage. In 100 g of fresh-cut apples, vitamin E content increased more than 100 times, and calcium and zinc contents increased about 20 times compared with unfortified apples. Consumer sensory study demonstrated that HFCS-treated apples were highly accepted by consumers in respect to overall liking, color, and texture quality. Bacterial growth was concurrently detected in all apples, but the total plate accounts were under 2.6 log colony-forming units (CFU)/ g apple at the end of 7 d of storage, significantly lower than the industrial standard. Instrumental analysis indicated that VI treatment in both HFCS and CC solutions significantly decreased color change and retained the firmness of fresh-cut apples during 3 wk of cold storage.