Physical, microbial, and chemical quality of hot-air-dried persimmon (diospyros kaki) chips during storage

Authors: Milczarek, Rebecca; Vilches, Ana; Olsen, Carl; Breksa, Andrew; Mackey, Bruce; Brandl, Maria

Submitted to: Journal of Food Quality
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/18/2020
Publication Date: 3/31/2020
Citation: Milczarek, R.R., Vilches, A.M., Olsen, C.W., Breksa III, A.P., Mackey, B.E., Brandl, M. 2020. Physical, microbial, and chemical quality of hot-air-dried persimmon (diospyros kaki) chips during storage. Journal of Food Quality. 2020. https://doi.org/10.1155/2020/7413689.
DOI: https://doi.org/10.1155/2020/7413689

Interpretive Summary: Asian persimmons are an underutilized tree fruit in the U.S. Recent efforts have been made to develop hot air-dried chips as a value-added product for this fruit. However, the long-term quality of the dried persimmon chips and its dependence on processing conditions and packaging type have not yet been explored. Hence, in this work, chips were prepared from ‘Hachiya’ persimmon fruit in 2 ways: 2 mm-thickness fruit slices hot-air dried for 5 hours (Preparation 2-5) and 5 mm slices dried for 10 hours (Preparation 6-10). The dried chips were then packaged into 2 bag types (plastic zip-top and Mylar with desiccant packets), stored under ambient conditions, and sampled for various quality traits throughout the 1-year storage study. It was found that all 4 preparation/packaging combinations yielded products which maintained acceptable quality throughout the entire study. Compared to Preparation 2-5 chips, Preparation 6-10 chips were preferred by consumers; however, they generally had lower contents of healthy nutrients – antioxidant compounds, ascorbic acid (Vitamin C), and carotenoids. Evidence of sugar degradation was found for Preparation 6-10 chips but not for Preparation 2-5 chips. For both Preparations, the contents of ascorbic acid and carotenoids experienced time-dependent decreases. Plastic zip-top bags and Mylar bags with desiccant packets performed equally well as packaging for most of the quality metrics tracked during this study. Overall, this work has demonstrated that hot air-drying of persimmon slices is a promising approach to create a value-added product with at least one year of shelf-life.

Technical Abstract: Recent efforts have been made to develop hot-air-dried chips as a value-added product for persimmon fruit (Diospyros kaki). However, the long-term quality of this product and its dependence on processing conditions and packaging type have not yet been explored. Hence, in this work, chips were prepared from “Hachiya” persimmon fruit in 2 ways: 2'mm thickness fruit slices, hot-air-dried for 5 hours (Preparation 2–5), and 6'mm slices, dried for 10 hours (Preparation 6–10). The dried chips were then packaged into 2 bag types (plastic zip-top and metallized polyethylene terephthalate (Met-PET) with desiccant packets), stored under ambient conditions, and sampled for moisture-related, microbial, texture, and chemical quality traits throughout the 1-year storage study. It was found that–with the exception of a marked decrease in ascorbic acid (vitamin C)—all 4 Preparation/Packaging combinations yielded products that maintained acceptable color, microbial, nutritional, and textural quality throughout the entire study. Compared to Preparation 2–5 chips, Preparation 6–10 chips generally had lower contents of healthy nutrients—antioxidant compounds, ascorbic acid, and carotenoids. Evidence of invertase activity was found for Preparation 6–10 chips but not for Preparation 2–5 chips. For both preparations, the contents of ascorbic acid and carotenoids experienced time-dependent decreases. Plastic zip-top bags and Met-PET bags with desiccant packets performed equally well as packaging for most of the quality metrics tracked during this study. Overall, this work has demonstrated that hot-air-drying of persimmon slices is a promising approach to create a value-added product with at least one year of shelf-life.