Virgin coconut oil: A comprehensive review of antioxidant activity and mechanisms contributed by phenolic compounds

Virgin coconut oil (VCO) is obtained by processing mature coconut cores with mechanical or natural methods. In recent years, VCO has been widely used in the food, pharmaceutical, and cosmetic industries because of its excellent functional activities. VCO has biological functions such as antioxidant, anti-inflammatory, antibacterial, and antiviral, and also has potential therapeutic effects on many chronic degenerative diseases. Among these functions, the antioxidant is the most basic and important function, which is mainly determined by phenolic compounds and medium-chain fatty acids (MCFAs). This review aims to elucidate the antioxidant functions of each phenolic compound in VCO, and discuss the antioxidant mechanisms of VCO in terms of the role of phenolic compounds with fat, intestinal microorganisms, and various organs. Besides, the composition of VCO and its application in various industries are summarized, and the biological functions of VCO are generalized, which should lay a foundation for further research on the antioxidant activity of VCO and provide a theoretical basis for the development of food additives with antioxidant activity.

Study of vegetable oils and their blends using infrared reflectance spectroscopy and refractometry

The present study aims to perform a comparative analysis of vegetable oils and their two-component blends using infrared spectroscopy and refractometry. The study was conducted in Almaty (Kazakhstan) in 2020. Three samples of 44 vegetable oils and their blends made from two components were examined. Fractometry and infrared spectroscopy were used to investigate the properties of blended vegetable oils. To this end, the fatty acid fraction (in percentage), iodine number, and index of refraction (IOR) were calculated. Afterward, the spectrograms obtained for the blends were analyzed. It was found that the difference between the intensities of weak bands and the band expansion of 722 cm^-1 indicates greater expressiveness. When low-intensity bands (1653 cm^-1) become more distinct due to vibrations of double carbon bonds (C-bonds), the level of unsaturated fatty acids in the blend increases as well.

A comprehensive review on the techniques for coconut oil extraction and its application

Virgin coconut oil is a useful substance in our daily life. It contains a high percentage of lauric acid which has many health benefits. The current industry has developed several methods to extract the oil out from the coconut fruit. This review paper aims to highlight several common extraction processes used in modern industries that includes cold extraction, hot extraction, low-pressure extraction, chilling, freezing and thawing method, fermentation, centrifugation, enzymatic extraction and supercritical fluid carbon dioxide. Different extraction methods will produce coconut oil with different yields and purities of lauric acid, thus having different uses and applications. Challenges that are faced by the industries in extracting the coconut oil using different methods of extraction are important to be explored so that advancement in the oil extraction technology can be done for efficient downstream processing. This study is vital as it provides insights that could enhance the production of coconut oil.

Rapid adulteration detection of cold pressed oils with their refined versions by UV-Vis spectroscopy

The aim of this study is the rapid detection of food pressed oils adulteration with their refined versions, using UV–Vis spectroscopy. The study investigates some common oil physico-chemical parameters such are: density, viscosity, refractive index, acid index, peroxide value, saponification index, to detect differences between cold pressed oils versus refined ones, for some food-grade oils found on Romanian market, as well as FT-IR spectroscopy and GC–MS analytical method, obtaining similar results to those presented in the literature data. The difference between some of the obtained results is not relevant for telling the cold-pressed oils from their refined version for adulteration investigation purpose. Colour analysis instead is a very good method to differentiate a cold pressed oil from a refined one. Taking this into account, the cold pressed oils and their refined versions were mixed in different proportions, and their colour properties were analyzed, obtaining linear dependences for a* and b* CIE L*a*b* parameters with cold pressed oil content in the mixture. Dependence equations were proposed.

Comparative study on extraction of virgin coconut oil with the aid of partially purified protease from seabass pyloric caeca and commercial trypsin

Coconut milk was hydrolyzed by partially purified protease from seabass pyloric caeca (PPSP) and commercial trypsin (CT) at various levels (5 and 10 unit/g protein) at 60°C for different hydrolysis times (0-150 min). At the same protease level and hydrolysis time, higher degrees of hydrolysis and larger droplet size were found in coconut milk hydrolyzed by PPSP, compared to CT. The highest virgin coconut oil (VCO) yield (77.34%) was observed after the sample was hydrolyzed for 150 min by PPSP (10 units/g protein). Protein patterns indicated that coconut milk proteins were more prone to hydrolysis by PPSP, compared to CT. A marked difference was not found in physicochemical properties of commercial VCO and VCO separated from coconut milk using PPSP. Therefore, VCO could be extracted using PPSP under optimal condition, wherein the extraction could be accomplished within a short time with high yield. PRACTICAL APPLICATIONS: In virgin coconut oil (VCO) manufacture, the yield of VCO and cost of the commercial enzyme are of main concern. Therefore, cheap source of proteases, particularly proteases from seabass pyloric caeca, can be a promising alternative for the manufacture of VCO. Therefore, the cost associated with commercial enzymes could be reduced and the proteases from seabass processing byproducts were better exploited.