Effect of Grinding at Modified Atmosphere or Vacuum on Browning, Antioxidant Capacities, and Oxidative Enzyme Activities of Apple

Abstract

This study evaluated the effects of grinding at atmospheric pressure (control), under vacuum (ß2.67 kPa), or with modified atmosphere (N 2 and CO 2 ) on the browning, antioxidant activity, phenolics, and oxidative enzyme activity of apples as a function of time. The control group was affected most, showing distinct browning and losing most of the antioxidant activity and concentrations of the main phenolic compounds. The modified atmosphere groups retained color, antioxidant activity, and phenolic compounds better than the control group. Least changes were obtained with vacuum grinding, particularly in terms of preventing enzymatic browning and oxidation of antioxidants apples. At 12 h after grinding, vacuum-ground apples retained total phenolic contents 5.32, 1.54, and 1.49 times higher than control, nitrogen gas, and carbon dioxide gas-ground samples, respectively. The oxidative enzyme activity, including that of polyphenol oxidase and peroxidase, decreased in the control and modified atmosphere group, but they were maintained in the samples ground under the vacuum.Keywords: apple, grinding, modified atmosphere, phenolic compounds, vacuumPractical Application: In this study, we found that grinding with modified atmosphere or vacuum conditions could effectively prevent browning as well as loss of phenolic compounds and antioxidant activity of ground apples. These results can help scientists and engineers build better grinding systems for retaining nutrient and quality factors of ground apples. In addition, these results may be useful to other fruit and vegetable industries that wish to retain fresh-like quality and nutritional value during grinding and storage.

Thermal and non-thermal processing of red-fleshed apple: how are (poly)phenol composition and bioavailability affected?

“…31 In freeze-dried samples, these reactions do not occur because the freezing and subsequent sublimation of water under vacuum conditions prevents the action of these enzymes and consequently the browning of the samples. 32 However, although this process efficiently preserves bioactives, freeze-drying costs can be 2-5 times higher than hot air-drying in order to achieve the same final moisture content. This fact justifies the need to find alternatives for the production of economically affordable healthy food for everyone.…”

Quality attributes and related enzyme activities in peppers during storage: effect of hydrothermal and calcium chloride treatment

“…Liu et al [44] had proved POD catalyzed various oxidation reactions involving CAT and caused enzymatic browning with PPO. Kim et al [45] also showed that PPO and POD were crucial for the oxidation of phenolic compounds and resulted in enzymatic browning. Liu et al [44] also found that POD was related to anti-browning of fresh-cut potato slices during storage.…”

Optimisation of Physical and Chemical Treatments to Control Browning Development and Enzymatic Activity on Fresh-cut Apple Slices

“…More than 50 per cent of foods susceptible to browning are wasted due to discolorations caused by enzymatic reactions [5]. Undesirable endogenous enzymatic reactions occur during intermediate processing operations such as fruit washing, cleaning, sorting, peeling, coring and cutting [6]. Polyphenol oxidase (PPO) and peroxidase (POD) are the two enzymes responsible for the oxidative browning reactions.…”