Quality Assessment Of Northeast Peach And Apricot Varieties And Their Value-Added Products
From 2009 to 2011, ten peach and five apricot varieties cultivated and commercially available in the Northeast were assessed for quality indices and phytochemical content. The objective was to generate qualitative and quantitative information on the phenolic, antioxidant, and carotenoid content of these varieties and how they were affected by seasonal variations, maturity at harvest, storage and processing. Selected varieties were made into value-added, shelf-stable products and evaluated after processing and storage for 6 months at 18-20 ˚C. Apricot products had higher phytochemical content compared to peaches. Varieties with greatest phenolic and antioxidant content were 'PF 22-007' peach and 'Hargrand' apricot while 'Babygold 5' peach and 'Hargrand' apricot had highest carotenoid content. Phenolic and antioxidant content generally decreased with on-tree ripening while these components remained relatively stable after harvest in cold storage. Carotenoid content increased three to six-fold in apricots with both on- and off-tree ripening. Individual phenolic and carotenoid compounds identified and quantified by HPLC were influenced by fruit type, variety and pre- and postharvest conditions. Evaluation of canned products showed a reduction of phytochemical content with peeling and storage. Losses of hydrophilic constituents were partly due to migration into syrup while lipophilic constituents were less susceptible to leaching. Pre-drying treatments significantly influenced dried fruit color and phytochemical content, with a sulfiting treatment the most effective. Two alternative treatments, blanching and rhubarb juice+blanching, proved promising in the production of dried fruit with acceptable color while retaining a good level of phenolic content and antioxidant capacity; a rhubarb juice-only treatment was suitable only for carotenoid retention. Fruit and sucrose content of jam and nectar influenced quality and phytochemical content. Increasing fruit content resulted in higher nutraceutical value post-processing and in storage; this effect was better assessed using HPLC. Overall results position peaches and apricots as important sources of phenolics, antioxidants and carotenoids, with apricots being good to excellent sources of vitamin A. Production, varietal selection and postharvest handling are important to maximize the nutraceutical quality of fresh fruits, while processing conditions and formulation can be optimized to retain healthful bioactive compounds thus providing better options for consumers.
Peach; Apricot; Phytochemicals
Padilla-Zakour, Olga I.
Worobo, Randy W.; Merwin, Ian Alexander
Food Science & Technology
Ph.D. of Food Science & Technology
Doctor of Philosophy
dissertation or thesis