Potato Glycoalkaloids: occurrence, biological activities and extraction for biovalorisation – a review

Abstract

Potato tuber (Solanum tuberosum L.) is the fourth most important agricultural product after wheat, rice and maize. With a total production of 388 million in 2017, c.a. 70% of this total production is processed in developed countries, producing a large amount of potato peel waste (PPW) as by-product. Although PPW is considered as a zero-value by-product by the feed industry because it is too fibrous, for other recycling industries it is an inexpensive by-product due to its significant contents of some interesting nutrients particularly polyphenols and glycoalkaloids. In potato, and Solanum species in general, many glycoalkaloids, predominantly a-chaconine and a-solanine, have been chemically and structurally identified. However, further research is needed to expand the knowledge of the biological values of potato glycoalkaloids in order to develop a recycling process to extract these technologically and nutritionally interesting bioactive ingredients for different sectors, in particular, the agricultural, food and pharmaceutical ones, which are demanding natural, safe and eco-friendly ingredients.

The effect of oven drying on bioactive compounds, antioxidant activity, and phenolic compounds of white and red‐skinned onion slices

“…The heating process of fresh vegetables can lead to oxidation, thermal degradation, and the leeching of bioactive compounds within the plants (Kalt, 2005; Singh et al., 2019). Several plants have antioxidant properties and additionally, varying heating conditions exert differing effects on the antioxidant properties of vegetables (Benkeblia, 2020; Ju & Song, 2020; Makris & Rossiter, 2001; Njume et al., 2020). As compared to red onions, yellow onions contain a higher level of quercetin, and white onions possess the lowest concentration of quercetin within them (Patil et al., 1995).…”

Sustainable Use of Bioactive Compounds from Solanum Tuberosum and Brassicaceae Wastes and by-Products for Crop Protection—A Review

“…A crucial and limiting issue is the optimization of the industrial multi-step process in the frame of a green strategy necessary for sustainable PPW exploitation [ 14 ]. The first critical point to be addressed is how to dry the starting fresh sample to obtain a stable and extractable matrix.…”

“…The “green” extraction alternative protocol should employ the use of water, but often this solvent is not effective, especially because of the low yields [ 97 ]. Ultrasound-assisted extraction (UAE) is a promising and innovative technique, well described by Bankeblia [ 14 ] and Hossain [ 98 ]. Additionally, the characterization and quantification of active principles in recovered by-products is carried out at the lab-scale by using complex chromatographic methods, such as HPLC (high-performance liquid chromatography) and HPTLC (high-performance thin-layer chromatography).…”

“…Minimizing the ‘yield gap’ and increasing yield stability under different stress conditions is the worldwide trend being emphasized. However, despite the increasing interest around the concept of circular economy, there are currently few systematic studies on extracts from wastes of Solanaceae and Brassicace ae that can explain their effects on plant pathogens due to a defined concentration of bioactive molecules [ 14 ].…”

“…Potato is the fourth major food crop in the world, with a production around 388 million tons [ 15 ], of which <50% is consumed fresh [ 14 ]. The large consumption of processed potato products (French fries, potato crisp, and frosted potatoes) causes a huge quantity of residues every year as Potato Peel Waste (PPW), a by-product of the large-scale peeling from manufacturing industries [ 16 ].…”