Innovative “Green” and Novel Strategies for the Extraction of Bioactive Added Value Compounds from Citrus Wastes—A Review

Abstract

Citrus is a major processed crop that results in large quantities of wastes and by-products rich in various bioactive compounds such as pectins, water soluble and insoluble antioxidants and essential oils. While some of those wastes are currently valorised by various technologies (yet most are discarded or used for feed), effective, non-toxic and profitable extraction strategies could further significantly promote the valorisation and provide both increased profits and high quality bioactives. The present review will describe and summarize the latest works concerning novel and greener methods for valorisation of citrus by-products. The outcomes and effectiveness of those technologies such as microwaves, ultrasound, pulsed electric fields and high pressure is compared both to conventional valorisation technologies and between the novel technologies themselves in order to highlight the advantages and potential scalability of these so-called “enabling technologies”. In many cases the reported novel technologies can enable a valorisation extraction process that is “greener” compared to the conventional technique due to a lower energy consumption and reduced utilization of toxic solvents.

Optimization of ultrasound‐assisted extraction of phenolic compounds from grapefruit (Citrus paradisi Macf.) leaves via D‐optimal design and artificial neural network design with categorical and quantitative variables

“…5 However, an efficient extraction process is necessary to obtain added-value products from biowastes. Over the last few years, suitable extraction methods have been investigated to obtain phytochemical compounds from biowastes, with higher efficiencies and reduced extraction times, [6][7][8][9][10] ultrasound-assisted extraction (UAE) being one of the most promising among other novel extraction techniques, since it needs lower amounts of solvents and reduced extraction times compared with conventional methods (solid-liquid or liquid-liquid extraction, grinding, maceration (soaking), percolation, counter-current extraction, pressurized liquid extraction, Soxhlet, etc.). 11,12 First, cavitation is the crucial effect of ultrasound because it leads to cell disruption and enhances mass transfer.…”

An Integrated Approach to Mandarin Processing: Food Safety and Nutritional Quality, Consumer Preference, and Nutrient Bioaccessibility

“…China is followed by Spain, Morocco, Turkey, Brazil, and Egypt, while Spain is the world's largest exporter of fresh mandarins, accounting for over 50% of the world's exports (FAO ). It has recently been reported that mandarins represent 22% of world's citrus production (FAO ) or positioned as second most produced citrus in the world (Putnik and others ), highlighting the importance of this crop. Anatomically speaking, mandarins are divided into pericarp (peel) and endocarp, with the pericarp branching into epicarp (flavedo) and mesocarp (albedo) see Figure .…”

Trends in Chemometrics: Food Authentication, Microbiology, and Effects of Processing

“…Many reports show that thermal processing of foods adversely affects the nutritional content and sensory properties of foods, but thermal treatment is still necessary for inactivating microbial pathogens and enzymes, in order to prolong shelf‐life (van Boekel et al., ). Raw fruits and vegetables (Poojary et al., ; Putnik et al., ; Putnik et al., ), their products (Bursać Kovačević et al., ), and byproducts (Putnik et al., ) are among the most sensitive materials for (thermal) processing, yet innovative applications of (nonthermal) technology can decrease or alleviate deterioration of important biologically active compounds. In these examples, use of multivariate statistics, especially multivariate regression, has enabled optimization of parameters.…”