Pressure and Temperature Effects on Degradation Kinetics and Storage Stability of Total Anthocyanins in Blueberry Juice

Abstract

The degradation kinetics of total anthocyanins in blueberry (Vaccinium myrtillus) juice were studied during thermal processing by treatment at selected temperatures (60-121 °C) and combined high pressure-temperature processing (100-700 MPa, 40-121 °C). Anthocyanin stability was also studied for several of these treatments during storage at 4, 25, and 40 °C. Both pressure and temperature increased d, the degradation rate of total anthocyanins in blueberry juice, meaning that at constant temperature, anthocyanins were more rapidly degraded with increasing pressure. For example, 32% degradation of anthocyanins was observed after 20 min heating at 100 °C and atmospheric pressure, whereas at 100 °C and 600 MPa, approximately 50% of total anthocyanins were lost. Degradation of anthocyanins was significantly accelerated with increasing storage temperatures. Combined pressure-temperature treatment of pasteurized juice led to a slightly faster degradation of total anthocyanins during storage compared to heat treatments at ambient pressure. Degradation of anthocyanins was best described by a 1.4th-order reaction at all conditions investigated. A mathematical model describing the degradation of blueberry anthocyanins in juice as a function of pressure, temperature, and treatment time is presented.

Green ultrasound-assisted extraction of anthocyanin and phenolic compounds from purple sweet potato using response surface methodology

“…Although some previous studies have demonstrated negative effects of high temperatures (>60ºC) (Buckow et al, 2010;Kechinski et al, 2010) on anthocyanin stability, the increase in anthocyanin yield with augmented extraction temperatures could be explained by multiple effects of temperature on the mass-transfer process such as improved diffusion, denaturation of the plant matrix, and improvement of solvent characteristics in terms of penetration and solubility of anthocyanins. Ultrasonic treatment combined with heating can induce the formation of localized micro fractures in cell walls, thus facilitating release of anthocyanins (Barba et al, 2015a(Barba et al, , 2015b, which are mainly found in the upper cell layers of the hypodermis.…”

Phytochemical uptake following human consumption of Montmorency tart cherry (L. Prunus cerasus) and influence of phenolic acids on vascular smooth muscle cells in vitro

“…The monomeric anthocyanin pigment content of the MC concentrate and aqueous Montmorency cherry fruit 106 extracts (whole frozen and dried) was determined using the pH-differential method [23]. The MC concentrate…”

Ricotta Cheese Whey-Fruit-Based Beverages: Pasteurization Effects on Antioxidant Composition and Color

“…Similarly to our results on the MAP content, studies on anthocyanin thermal degradation in blueberry juices have highlighted that the reaction follows a first-order kinetics process, and that the kinetic rate constant k value increases with temperature, i.e. that a greater degradation occurs at higher processing temperatures [42][43][44]. Since one of the most important reactions occurring during anthocyanin thermal degradation is polymerization, Martynenko and Chen [44] suggested the use of PC as a good indicator for anthocyanin degradation, as they found a strong negative exponential relationship between anthocyanin content and PC.…”