Stability of color and biologically active compounds of pasteurized juices from potatoes with colored flesh

Juices from potato varieties with colored flesh contain a large amount of biologically active compounds, but they tend to darken enzymatically, which deteriorates the quality. One of the factors that can improve the color of juices is pasteurization. The aim of the study was to investigate the effect of pasteurization temperature on the anthocyanin content and color of juices from potatoes with colored flesh. The research material included juices from potato varieties with red and purple flesh. Juices pasteurized at 75 °C were characterized by the lightest color and an increase in the a* (red color) and b* (yellow color) parameters compared to unpasteurized juices. Pasteurization of juices reduced the amount of glycoalkaloids by an average of 54% compared to unpasteurized juices (larger losses in the content of α-chaconine than α-solanine). Purple potato juices showed a higher content of total polyphenols by an average of 30% and anthocyanins by 70% than juices from red potatoes. Pelargonidin and its derivatives were identified in red potato juices, while petunidin and peonidin were the most abundant in purple potato juices. Higher losses of total polyphenols were found in juices from red varieties of potatoes, while anthocyanins were less thermostable in juices from varieties with purple flesh.

Comparison of Physicochemical, Antioxidant, and Cytotoxic Properties of Caffeic Acid Conjugates

Spectroscopic studies (FT-IR, Raman, 1H, and 13C NMR, UV-VIS) of caffeic acid (CFA) and its conjugates, i.e., caftaric acid (CTA), cichoric acid (CA), and cynarin (CY), were carried out. The antioxidant activity of these compounds was determined by a superoxide dismutase (SOD) activity assay and the hydroxyl radical (HO•) inhibition assay. The cytotoxicity of these compounds was performed on DLD-1 cell lines. The molecules were theoretically modeled using the B3LYP-6-311++G(d,p) method. Aromaticity indexes (HOMA, I6, BAC, Aj), HOMO and LUMO orbital energies and reactivity descriptors, NBO electron charge distribution, EPS electrostatic potential maps, and theoretical IR and NMR spectra were calculated for the optimized model systems. The structural features of these compounds were discussed in terms of their biological activities.

Advances in the Modulation of Potato Tuber Dormancy and Sprouting

The post-harvest phase of potato tuber dormancy and sprouting are essential in determining the economic value. The intricate transition from dormancy to active growth is influenced by multiple factors, including environmental factors, carbohydrate metabolism, and hormonal regulation. Well-established environmental factors such as temperature, humidity, and light play pivotal roles in these processes. However, recent research has expanded our understanding to encompass other novel influences such as magnetic fields, cold plasma treatment, and UV-C irradiation. Hormones like abscisic acid (ABA), gibberellic acid (GA), cytokinins (CK), auxin, and ethylene (ETH) act as crucial messengers, while brassinosteroids (BRs) have emerged as key modulators of potato tuber sprouting. In addition, jasmonates (JAs), strigolactones (SLs), and salicylic acid (SA) also regulate potato dormancy and sprouting. This review article delves into the intricate study of potato dormancy and sprouting, emphasizing the impact of environmental conditions, carbohydrate metabolism, and hormonal regulation. It explores how various environmental factors affect dormancy and sprouting processes. Additionally, it highlights the role of carbohydrates in potato tuber sprouting and the intricate hormonal interplay, particularly the role of BRs. This review underscores the complexity of these interactions and their importance in optimizing potato dormancy and sprouting for agricultural practices.

Food-Waste Valorisation: Synergistic Effects of Enabling Technologies and Eutectic Solvents on the Recovery of Bioactives from Violet Potato Peels

The recovery of valuable bioactive compounds from the main underutilised by-products of the food industry is one of the greatest challenges to be addressed in circular economy. Potato peels are the largest waste generated during potato processing. However, they could be a potential source of valuable bioactive compounds, such as polyphenols, that can be reused as natural antioxidants. Currently, environmentally benign enabling technologies and new types of non-toxic organic solvents for the extraction of bioactive compounds may dramatically improve the sustainability of these processes. This paper focuses on the potential inherent in the valorisation of violet potato peels (VPPs) by recovering antioxidants using natural deep eutectic solvents (NaDES) under ultrasound (US)- and microwave (MW)-assisted extraction. Both the enabling technologies provided performances that were superior to those of conventional extractions in terms of antioxidant activity determined by the DPPH· (2,2-diphenyl-1-picrylhydrazyl) assay. In particular, the most promising approach using NaDES is proven to be the acoustic cavitation with a Trolox eq. of 1874.0 mmolTE/gExtr (40 °C, 500 W, 30 min), vs. the 510.1 mmolTE/gExtr of hydroalcoholic extraction (80 °C, 4 h). The shelf-life of both hydroalcoholic and NaDES-VPPs extracts have been assessed over a period of 24 months, and found that NaDES granted a 5.6-fold shelf-life extension. Finally, the antiproliferative activity of both hydroalcoholic and NaDES-VPPs extracts was evaluated in vitro using the MTS assay on human tumour Caco-2 cells and normal human keratinocyte cells (HaCaT). In particular, NaDES-VPPs extracts exhibited a significantly more pronounced antiproliferative activity compared to the ethanolic extracts without a noteworthy difference between effects on the two cell lines.

Optimization of Ultrasound-Assisted Extraction of Chlorogenic Acid from Potato Sprout Waste and Enhancement of the In Vitro Total Antioxidant Capacity

Potato sprouts, an underutilized by-product of potato processing, could be exploited for the recovery of caffeoyl-quinic acids (CQAs), a family of polyphenols with well-recognized biological activities. In this work, the predominant compound of this class, 5-CQA, was extracted by Ultrasound-Assisted Extraction (UAE) under conditions optimized by an Experimental Design. The investigated variables solid/solvent ratio (1:10-1:50 g/mL), water content in ethanol (30-100% v/v) and UAE time (5-20 min) highlighted a critical influence of the last two factors on the extraction efficiency: extracts richer in 5-CQA were obtained with lower water content (30%) and time (5 min). The addition of ascorbic acid (1.7 mM) as anti-browning agent to the extraction solvent improved the extraction efficiency of 5-CQA compared to acetic and citric acids (3158.71 μg/mL, 1766.71 μg/mL, 1468.20 μg/mL, respectively). A parallel trend for the three acids and an increase in 5-CQA recovery was obtained with the use of freeze-dried sprouts (4980.05 μg/mL, 4795.62, 4211.25 μg/mL, respectively). Total antioxidant capacity (TAC) in vitro demonstrated UAE being a more valuable technique than conventional maceration. Furthermore, three-times-higher values of TPC (7.89 mg GAE/g) and TAC (FRAP: 24.01 mg TE/g; DPPH: 26.20 mg TE/g; ABTS 26.72 mg TE/g) were measured for the optimized extract compared to the initial one. An HPLC-DAD method was applied to monitor 5-CQA recovery, while an LC-HRMS/MS investigation allowed us to perform analyte identity confirmation along with detection of the glycoalkaloids α-solanine and α-chaconine. This evidence underlines the necessity to develop purification strategies in order to maximize the potential of potato sprout waste as a source of 5-CQA.

Bioactive Substances of Potato Juice Reveal Synergy in Cytotoxic Activity against Cancer Cells of Digestive System Studied In Vitro

More and more literature data indicate the health-promoting effect of potato juice (PJ). However, to date, it has not been precisely explained which of the many compounds present in PJ exhibit biological activity. The work aimed to establish the antiproliferative effect of gastrointestinal digested PJ and the products of its processing. Fresh PJs derived from three edible potato varieties, industrial side stream resulting from starch production, partially deproteinized PJ derived from feed protein production line, and three different potato protein preparations subjected to digestion in the artificial gastrointestinal tract were used in this study. The cytotoxic potential of glycoalkaloids (GAs), phenolic acids, digested PJ, and products of PJ processing was determined in human normal and cancer cells derived from the digestive system. The results showed that GAs exhibit concentration-dependent cytotoxicity against all analyzed cell lines. In contrast, phenolic acids (caffeic, ferulic, and chlorogenic acid) do not show cytotoxicity in the applied cell lines. A correlation between cytotoxic potency and GAs content was found in all PJ products studied. The most potent effects were observed under treatment with deproteinized PJ, a product of industrial processing of PJ, distinguished by the highest effective activity among the fresh juice products studied. Moreover, this preparation revealed a favorable cytotoxicity ratio towards cancer cells compared to normal cells. Statistical analysis of the obtained results showed the synergistic effect of other bioactive substances contained in PJ and its products, which may be crucial in further research on the possibility of using PJ as a source of compounds of therapeutic importance.

Novel zero waste tactics for commercial vegetables – recent advances

Commercial vegetables include tomatoes, potatoes, onions, and eggplant due to their surplus production, availability, and affordability. The valorisation of the massive wastage of commercial vegetables and providing a long-term solution has been challenging. The review addresses the implications of biowastes on the environment and fosters the recent investigations into valorising commercial vegetable waste to develop multiple value-added products. It discussed the outcomes of the multiple technologies, majorly on green chemistry extraction, while outlining other methods such as fermentation, enzymatic treatments, 3D printing foods, high-pressure homogenisation, microencapsulation, bio-absorption method, and pyrolysis for their respective vegetable wastes. Agri-residues can be a valuable source for formulating functional ingredients, natural additives, biodiesel, dyes, and animal feed. This comprehensive review proposes a strategy to upcycle low-cost biowaste to boost the economic and ecological benefits. The current review captures the interests and great collaborations between researchers, industrialists, policymakers, waste management bodies, and eco-activists.

Fruit and Vegetable Peel-Enriched Functional Foods: Potential Avenues and Health Perspectives

Fresh fruit and vegetables are highly utilized commodities by health-conscious consumers and represent a prominent segment in the functional and nutritional food sector. However, food processing is causing significant loss of nutritional components, and the generation of waste is creating serious economic and environmental problems. Fruit and vegetables encompass husk, peels, pods, pomace, seeds, and stems, which are usually discarded, despite being known to contain potentially beneficial compounds, such as carotenoids, dietary fibers, enzymes, and polyphenols. The emerging interest in the food industry in the nutritional and biofunctional constituents of polyphenols has prompted the utilization of fruit and vegetable waste for developing enriched and functional foods, with applications in the pharmaceutical industry. Moreover, the utilization of waste for developing diverse and crucial bioactive commodities is a fundamental step in sustainable development. Furthermore, it provides evidence regarding the applicability of fruit and vegetable waste in different food formulations especially bakery, jam, and meat based products.

Potential use of plant-based by-products and waste to improve the quality of gluten-free foods

The food industry generates a large amount of waste and by-products, the disposal of which has a negative impact on the environment and the economy. Plant-based waste and by-products are rich in bioactive compounds such as dietary fiber, proteins, essential fatty acids, antioxidant compounds, vitamin, and minerals, which can be exploited to reduce the nutritional deficiencies of gluten-free products. The latter are known to be rich in fats and carbohydrates but lacking in bioactive compounds; the absence of gluten also has a negative effect on textural and sensory properties. Several attempts have been made to improve the quality of gluten-free products using alternative flours and additives, or by adopting innovative technologies. The exploitation of plant-based by-products would represent a chance to improve both the nutritional profile and the overall quality of gluten-free foods by further enhancing the sustainability of the agri-food system. After examining in detail the composition of plant-based by-products and waste, the objective of this review was to provide an overview of the effects of their inclusion on the quality of gluten-free products (bread, pasta, cake/muffins, biscuits and snacks). The advantages and drawbacks regarding the physical, sensory, and nutritional properties were critically evaluated. © 2021 Society of Chemical Industry.

Identification and Recovery of Valuable Bioactive Compounds from Potato Peels: A Comprehensive Review

Nowadays, the potato is one of the most cultivated and consumed food crops in the world and, in recent years, its production has experienced a sharp increase. Its industrial processing generates several by-products that are wasted and cause economic and environmental problems. Among them, potato peel stands out, representing up to 10% of the total potato residues obtained in the processing. On the other hand, these wastes, in addition to presenting antioxidant compounds, are rich in interesting chemical compounds of great value in a biorefinery model. This review summarizes the main compounds present in potato skins as well as the most used and innovative extraction methods employed for their isolation, with special emphasis on the fractions with biological activities. In addition, a sustainable biorefinery proposal focused on obtaining high added-value products with potential applications in the pharmaceutical, food, nutraceutical, or cosmetic industries is included.

Evaluation of Direct Ultrasound-Assisted Extraction of Phenolic Compounds from Potato Peels

Potato peels (PPs) are generally considered as agriculture waste. The United States alone generates over one million tons of PPs a year. However, PPs contain valuable phenolic compounds with antioxidant activities. In this study, we evaluated the efficiency of ultrasound-assisted extraction techniques in recovering antioxidants from PPs. These techniques included a direct ultrasound-assisted extraction (DUAE), an indirect ultrasound-assisted extraction (IUAE), and a conventional shaking extraction (CSE). Results of this study showed that DUAE was more effective in extracting phenolic compounds than IUAE and CSE. We also evaluated the factors affecting the yield of total phenolic compounds (TPC) in DUAE, including the temperature, time, acoustic power, ratio of solvent to solids, and size of PPs particles. TPC yield of DUAE was higher, and the extraction rate was faster than IUAE and CSE. Furthermore, TPC yield was strongly correlated to the temperature of the mixture of PPs suspension. SEM images revealed that the irradiation of ultrasound energy from DUAE caused micro-fractures and the opening of PPs cells. The extract obtained from DUAE was found to have antioxidant activity comparable to commercial synthetic antioxidants. Results of this preliminary study suggest that DUAE has the potential to transform PPs from agricultural waste to a valuable ingredient. A future systematic research study is proposed to advance the knowledge of the impact of processing parameters in the kinetics of phenolic compounds extraction from potato peels using various extraction methods.

Oral administration of potato peel extract affects serum blood metabolites, liver function and ameliorating oxidative stress induced in rabbits exposed to cold stress

This study investigated the effect of potato peel extract (PPE), orally administrated to rabbits, on serum blood metabolites and ameliorating oxidative stress induced by cold stress under Egyptian winter conditions. Twenty-four bucks grouped into three treatments (8 animals per group) were used for the experiment. The animals received 1.5 ml of water orally, containing 0 (PPE0), 25 (PPE25) or 50 (PPE50) mg PPE/kg live weight. Bucks were randomly assigned into three homogenous equal groups according to the level of PPE. Treatments were applied to each animal every two days over a period of three months including one month as an adaptation period. At the 8th week of the experiment, blood samples were collected from each buck and at the end of the experiment, bucks were slaughtered, and some organs were collected and weighed. The PPE improved (p < 0.05) blood total protein, albumin, globulin and glucose. The blood concentration of total lipid, cholesterol, triglyceride, low density lipoprotein and very low-density lipoprotein (were increased (p < 0.02) in PPE rabbits. Furthermore, PPE extract doses decreased (p < 0.001) oxidant thiobarbituric reactive substance (TBARS) in both blood and liver. Other liver and blood antioxidant system enzymes such as catalase, glutathione peroxidase, and superoxide dismutase were improved (p < 0.005) by PPE supplementation. Overall, oral administration of PPE up to 50 mg/kg live weight can have positive effects on rabbit health under cold stress.