Nonenzymatic Browning Criteria to Sea Buckthorn Juice during Thermal Processing

Abstract

Nonenzymatic browning reaction is responsible for color and quality changes of fruit juices during thermal processing, and reasonable criteria are crucially important for establishing good manufacturing practice. The nonenzymatic browning criteria of thermally treated sea buckthorn juice from 90 to 120C, i.e., the absorbance at 420 nm (A420nm) and color difference (ΔE*), were investigated. The values of L*, a*, b* and the content of ascorbic acid of sea buckthorn juice during thermal treatment could be fitted to first-order kinetics, while the formation of 5-hydroxymethylfurfural (5-HMF) followed a zero-order kinetics. The changes of ΔE* and A420nm could be estimated by integrated models. The thermal processing parameters for sea buckthorn juice were optimized using kinetic models with low level of 5-HMF and high content of ascorbic acid, and it was found that the thermal processing should be performed at 110C for 0.585 min. Estimation of the activation energy showed that A420nm could be a reasonable indicator for evaluating the nonenzymatic browning of thermally processed sea buckthorn juice from 90 to 110C and ΔE* could be a valuable index at 120C. PRACTICAL APPLICATIONSFor fruit juice (puree) processing, optimal parameters are critically important to manufacture products with high quality. During thermal processing, vitamin C degradation, 5-hydroxymethylfurfural accumulation and nonenzymatic browning occur simultaneously. The high quality includes the high vitamin content, the favorable appearance, the smallest color difference between raw material and final product, etc. This article discussed color changes of sea buckthorn juice, a superfruit juice specialized in high vitamin C content and low pH value, during thermal sterilization. Absorbance at 420 nm (A420nm) and color differences (ΔE*), two indicators in controlling nonenzymatic browning during juice processing, were evaluated with kinetic models and used to optimize the thermal processing. Furthermore, the activation energy calculation of A420nm and ΔE* revealed the reasonable criteria on juice quality controlling. All the quality control criteria in this paper showed a guideline of quality control in practical juice manufacturing.

Cross-Linked Microencapsulation of CO2 Supercritical Extracted Oleoresins from Sea Buckthorn: Evidence of Targeted Functionality and Stability

“…For example, some of the main nutrients, lipids with highly valued fatty acid composition, contribute to the nutritional benefits of sea buckthorn products for consumers. The importance of sea buckthorn is due to well-known positive biological, physiological, and medicinal effects, such as: antioxidative and immunomodulating [2], cardioprotective and antiatherogenic [3,4], antibacterial and antiviral effects [5], healing effect on acute and chronic wounds [6,7], anti-inflammatory [8], antidiabetic [9], anticarcinogenic [10], hepatoprotective and dermatological effects [11] etc.…”

Browning, Starch Gelatinization, Water Sorption, Glass Transition, and Caking Properties of Freeze-dried Maca (<i>Lepidium meyenii</i> Walpers) Powders

“…This was a consequence of air-drying and thermal sterilization during processing. 23) 24) Interestingly, the freeze-dried purple and white maca powders showed slightly higher OD 420 values than the yellow and black ones. It is known that the carbohydrates in maca consist of 23 % starch, 19 % sugars, 9 % water-soluble fiber, and 23 % water-insoluble fiber.…”

Encapsulation artocarpanone and ascorbic acid in O/W microemulsions: Preparation, characterization, and antibrowning effects in apple juice

“…It was strange to find that 0.5% VcME also showed strong antibrowning effects in 24 h. Although Vc exhibited good antibrowning effects in the initial stage, the degradation and oxidation of Vc would gradually increase over time. Furthermore, the degradation products from Vc could react with amino compounds to form brown pigments (Wibowo et al, 2015;Xu, Hao, Yuan, & Gao, 2015). Therefore, the single extensive use of Vc to inhibit the browning is not a good choice in the late stage.…”