Impact of the Ripening Stage of Wax Apples on Chemical Profiles of Juice and Cider.

Wax apple fruit (Syzygium aqueum Alston cv. Taaptimjan) is a tropical fruit with many nutritional bioactive compounds and high economic value. However, when fully ripe, the thin-skinned fruit is highly susceptible to physical damage and microbial spoilage that significantly reduce its commercial value. The present study was aimed to find a suitable ripening stage between the ripe and overripe wax apple fruits for developing a value-added beverage specifically cider. The chemical profiles of ripe and overripe wax apple juice and cider were determined by measuring sugar, acid, alcohol, mineral, proximate, ascorbic acid, amino acid, antioxidant, and volatile levels. Overall, the results showed significant variations. The physicochemical and proximate analysis showed highest values for ripe fruit juice than overripe fruit juice and the cider samples. The amino acids in the samples were found almost at similar levels. Polyphenolic content and antioxidant activities were higher in ciders than in unfermented juices. In addition, the overripe fruit cider had more volatile compounds than ripe fruit cider and unfermented juices. Overall, the overripe fruit is suitable for producing cider, whereas the ripe fruit is more suitable for the unfermented beverages.

Effects of Peach Cultivar on Enzymatic Browning Following Cell Damage from High-Pressure Processing.

Peach cultivars contribute to unique product characteristics and may affect the degree of browning after high-pressure processing (HPP). Nine peach cultivars were subjected to HPP at 0, 100, and 400 MPa for 10 min. Proton nuclear magnetic resonance (1H NMR) relaxometry, light microscopy, color, polyphenol oxidase (PPO) activity, and total phenols were evaluated. The development of enzymatic browning during refrigerated storage occurred because of damage during HPP that triggered loss of cell integrity, allowing substrates to interact with enzymes. Increasing pressure levels resulted in greater damage, as determined by shifts in transverse relaxation time (T2) and by light micrographs. Discoloration was triggered by membrane decompartmentalization but limited by PPO activity, which was found to correlate to cultivar harvest time (early, mid, and late season). Outcomes from the microstructure, 1H NMR ,and PPO activity evaluation were an effective means of determining membrane decompartmentalization and allowed for prediction of browning scenarios.

The Impact of Maturity Stage on Cell Membrane Integrity and Enzymatic Browning Reactions in High Pressure Processed Peaches (Prunus persica).

Fruit maturity is an important factor associated with final product quality, and it may have an effect on the level of browning in peaches that are high pressure processed (HPP). Peaches from three different maturities, as determined by firmness (M1 = 50-55 N, M2 = 35-40 N, and M3 = 15-20 N), were subjected to pressure levels at 0.1, 200, and 400 MPa for 10 min. The damage from HPP treatment results in loss of fruit integrity and the development of browning during storage. Increasing pressure levels of HPP treatment resulted in greater damage, particularly in the more mature peaches, as determined by shifts in transverse relaxation time (T2) of the vacuolar component and by light microscopy. The discoloration of peach slices of different maturities processed at the same pressure was comparable, indicating that the effect of pressure level is greater than that of maturity in the development of browning.