Impact of processing and storage conditions on color stability of strawberry puree: The role of PPO reactions revisited

Abstract

The effect of pre-heating fresh strawberries (hot break) and the use of refrigerated temperatures prior to pasteurization on the stability of anthocyanins, vitamin C, color and polyphenol oxidase (PPO) activity during storage (42 days at 35 ºC) of strawberry puree was studied. Hot break resulted in 20% residual PPO activity and caused 10% anthocyanin degradation, whereas vitamin C was unaffected. After mashing, purees were stored at 4 ºC and 25 ºC for 3 hours. During this period, anthocyanins and PPO activity remained constant independently of the processing history but ascorbic acid was oxidized faster at 25 ºC.Pasteurization caused complete inactivation of PPO, reduction of anthocyanins (25%), of a* value (6%) and of vitamin C (50%). Neither partial inactivation of PPO early in the processing (hot break) nor the use of refrigeration prior to pasteurization had a positive effect on color and anthocyanin stability of strawberry puree during subsequent storage, suggesting that PPO-derived reaction products formed during processing have a very limited impact on color degradation during shelf-life. Highlights• Different strawberry puree manufacturing processing conditions were evaluated • Hot break did not improve color stability during further processing and storage• Refrigeration prior to pasteurization prevented ascorbic acid oxidation • PPO reactions before pasteurization do not affect color degradation during storage

Comparative elucidation of bioactive and volatile components in dry mature jujube fruit (Ziziphus jujuba Mill.) subjected to different drying methods

“…1 b), with FD giving the highest value, followed by CD80. In the CD process, the plant cell structure is gradually broken, causing phenolics to be released from the cell matrix ( Teribia et al, 2021 ). Phenolic release drives substrate exposure to phenol oxidase and peroxidase, which provokes a strong enzymatic reaction, leading to the extensive phenolic depletion of samples CD40 and CD50 ( Chumroenphat et al, 2021 ).…”

Impact of High-Pressure Processing on Antioxidant Activity during Storage of Fruits and Fruit Products: A Review

“…The activity was inactive when the processing temperature was higher than 80 • C. In addition, β-glucosidase activity was significantly decreased with increasing temperature. However, undesirable changes in taste, color, and aroma may occur after heat treatment [92,[94][95][96][97]. In addition, high temperatures may reduce the nutritional value and functionality of bioactive compounds found in fruits and fruit-based products [95,[98][99][100].…”

Reaction pathways and factors influencing nonenzymatic browning in shelf‐stable fruit juices during storage

“…reported a decrease in a * value (redness) and an increase in ΔE * value during storage of pasteurized strawberry juice at 20 to 42 • C. At all temperatures, the L * and b * values were rather stable. Teribia et al (2021) (Wibowo et al, 2015d). The observed color changes of orange, strawberry, and mango juice/puree during storage are most probably due to a combination of the degradation of the naturally occurring pigments (i.e., carotenoids or anthocyanins) and the formation of brown colored compounds.…”

“…Browning of fruit-based products can result from two types of reactions: enzymatic and nonenzymatic reactions. Enzymatic browning reactions are mainly attributed to the activity of polyphenol oxidase and peroxidase and can be controlled by the application of thermal treatment (e.g., a pasteurization) whether or not in combination with the use of additives (Martinez & Whitaker, 1995;Teribia et al, 2021;Vámos-Vigyázó, 1981). It is generally agreed that nonenzymatic browning (NEB) in fruit juices is due to an interplay of reactions involving ascorbic acid (AA), sugars, and amino acids (Bharate & Bharate, 2014;Corzo-Martínez et al, 2012;Handwerk & Coleman, 1988).…”