Pulsed electric fields using a multiple needle chamber to improve bioactive compounds extraction from unprocessed Opuntia ficus-indica fruits

Polyphenol Extraction from Food (by) Products by Pulsed Electric Field: A Review

Nowadays, more and more researchers engage in studies regarding the extraction of bioactive compounds from natural sources. To this end, plenty of studies have been published on this topic, with the interest in the field growing exponentially. One major aim of such studies is to maximize the extraction yield and, simultaneously, to use procedures that adhere to the principles of green chemistry, as much as possible. It was not until recently that pulsed electric field (PEF) technology has been put to good use to achieve this goal. This new technique exhibits many advantages, compared to other techniques, and they have successfully been reaped for the production of extracts with enhanced concentrations in bioactive compounds. In this advancing field of research, a good understanding of the existing literature is mandatory to develop more advanced concepts in the future. The aim of this review is to provide a thorough discussion of the most important applications of PEF for the enhancement of polyphenols extraction from fresh food products and by-products, as well as to discuss the current limitations and the prospects of the field.

Effect of heat and pulsed electric field treatment on the physicochemical and nutritional properties of carrots

BACKGROUND

Carrots are widely used in home cooking and vegetable processing industries because of their high nutritional value. However, different processing methods may produce a negative impact on carrot texture and nutrition quality. Therefore, the development of better processing methods to preserve the texture and nutrition quality of carrots will be beneficial to the carrot industry.

RESULTS

The effects of heat and pulsed electric field (PEF) treatments with different heat temperatures (T) and holding time (t_h ) on comprehensive changes in thermal efficiency profiles, and physicochemical (color, hardness, cell structural damage) and nutritional (releasable β-carotene contents) properties of carrots were studied. In addition, electrical conductivity (σ) and soluble matter contents (°Brix) were determined for the heat-treated extracts. The value of total color difference (∆E) and cell structural damage index (Z) of carrots, σ and °Brix of extracts all increased with increasing T and t_h under different heat experimental conditions, whereas the value of cutting force (F) presented an opposite tendency and content of releasable β-carotene decreased after t_h  > 2 min at T = 100 °C.

CONCLUSION

The results show that PEF heating is beneficial in preventing changes in physicochemical and nutritional properties of carrots compared to traditional heat treatment. PEF has potential as a heating technology in the food industry. © 2022 Society of Chemical Industry.

Opuntia ficus-indica Fruit: A Systematic Review of Its Phytochemicals and Pharmacological Activities

The use of Opuntia ficus-indica fruits in the agro-food sector is increasing for a multiplicity of players. This renewed interest is, in part, due to its organoleptic characteristics, nutritional value and health benefits. Furthermore, industries from different sectors intend to make use of its vast array of metabolites to be used in different fields. This trend represents an economic growth opportunity for several partners who could find new opportunities exploring non-conventional fruits, and such is the case for Opuntia ficus-indica. O. ficus-indica originates from Mexico, belongs to the Cactaceae family and is commonly known as opuntia, prickly pear or cactus pear. The species produces flowers, cladodes and fruits that are consumed either in raw or in processed products. Recent publications described that consumption of the fruit improves human health, exhibiting antioxidant activity and other relevant pharmacological activities through enzymatic and non-enzymatic mechanisms. Thus, we provide a systematic, scientific and rational review for researchers, consumers and other relevant stakeholders regarding the chemical composition and biological activities of O. ficus-indica fruits.

A review of the polyphenols extraction from apple pomace: novel technologies and techniques of cell disintegration

Apple pomace, a solid waste produced during industrial processing of apple juice or cider, is a rich source of high value-added compounds such as polyphenols. This review summarizes present studies on the qualitative and quantitative methods, including Folin-Ciocalteu colorimetric, high pressure liquid chromatography (HPLC) and fluorescence spectrum, as well as enhanced extraction methods of polyphenols in apple pomace by different traditional and novel technologies, including ultrasounds (US), microwave (MW), pulsed electric fields (PEF), high voltage electrical discharges (HVED) and enzyme. The principles and characteristics of different effective enhanced extraction technologies of polyphenols in apple pomace were compared. In addition, the different cell disruption analysis methods, such as destructive detection method (electrical conductivity disintegration index, Zc), image analysis method (including scanning electron microscopy, SEM, and confocal laser scanning microscopy, CLSM), and nondestructive method (such as magnetic resonance imaging, MRI) are presented in this review. The study proved that there was a correlation between destructive detection method and image analysis method. However, each of the technologies reviewed in this study has some disadvantages to overcome, and some mechanisms need to be further substantiated. Therefore, more competitive techniques for polyphenols extraction and analysis of cell disintegration are needed to emerge in the future.