Thermal and nonthermal pretreatment methods for the extraction of anthocyanins: A review

Abstract

Functional plant bioactive such as polyphenols have drawn greater interest for researchers, food industries, and consumers. Anthocyanins are popular due to its high antioxidant activity and nutra‐pharmaceutical potential. As the demand for anthocyanins grows, exploring and acknowledging applications of various conventional and nonconventional means of anthocyanin extraction is important. Conventional extraction methods have some limitations in the context that these are most time‐consuming, tedious, and less cost‐effective as well as offer lower extraction yield and selectivity. Therefore, to encounter the limitations mentioned, pretreatments including thermal and nonthermal are applied to plant materials prior to the conventional bioactive extraction process. Thermal pretreatments include blanching, ultrasonication, microwave, and ohmic heating (OH); meanwhile, examples of nonthermal pretreatment are enzymatic, high‐pressure processing (HPP), and pulsed electric field (PEF). This review is an attempt to critically summarize the applications of various pretreatment methods for improving the extraction rates and yields of anthocyanins from plant materials. Novelty impact statement Overall, ohmic heating (OH) appeared as the best thermal pretreatment prior to anthocyanins conventional extraction method due to rapid heating and low energy consumption. On the other hand, the most efficient nonthermal pretreatment method is high‐pressure processing (HPP) due to its rapid process, as well as successfully inactivate the microbial and enzyme activities.

Recovery of anthocyanins from Eugenia spp. fruit peels: a comparison between heat- and ultrasound-assisted extraction

“…Hence, an adequate balance between these two process factors is pivotal to achieve successful anthocyanin recovery. 34…”

Influence of Different Drying Methods on Anthocyanins Composition and Antioxidant Activities of Mangosteen (Garcinia mangostana L.) Pericarps and LC-MS Analysis of the Active Extract

“…This finding is in agreement with Çoklar and Akbulut [ 51 ], who found that drying of black grapes using freeze-drying (−110 °C, 48 h) increased 16% of anthocyanins, but reduced 95% of these compounds in both oven- (60 °C, 17 h) and sun-dried (7 days) samples compared to fresh (~1752.94 mg/kg). Drying anthocyanins-rich plants will accelerate the extraction and allow penetration of solvent into cells and extract the targeted compounds while maintaining the chemical properties of anthocyanins [ 52 ]. Considering anthocyanins that are sensitive to light and heat, exposing the MP to direct sunlight for longer periods led to the degradation of heat-sensitive compounds, particularly anthocyanins.…”

Nutritional and therapeutic benefits of coconut milk and its potential as a plant-based functional yogurt alternative: a review

“…As CM is low in Ca and acceptance, fortification in form of flavoring can be considered to achieve a good dairy alternative. To be more natural, additives from plant-based materials are desirable [112,113] . For example, certain vegetables such as Cosmos caudatus and water spinach contain an excellent amount of Ca and can easily be cultivated as they possess weed-like characteristics and grow in abundance [114] .…”