Analysis of phenolic compounds by high-performance liquid chromatography and liquid chromatography/mass spectrometry in potato plant flowers, leaves, stems, and tubers and in home-processed potatoes

Potato Berries as a Valuable Source of Compounds Potentially Applicable in Crop Protection and Pharmaceutical Sectors: A Review

Potato (Solanum tuberosum) is a major agricultural crop cultivated worldwide. To meet market demand, breeding programs focus on enhancing important agricultural traits such as disease resistance and improvement of tuber palatability. However, while potato tubers get a lot of attention from research, potato berries are mostly overlooked due to their level of toxicity and lack of usefulness for the food production sector. Generally, they remain unused in the production fields after harvesting the tuber. These berries are toxic due to high levels of glycoalkaloids, which might confer some interesting bioactivities. Berries of various solanaceous species contain bioactive secondary metabolites, suggesting that potato berries might contain similarly valuable metabolites. Therefore, possible applications of potato berries, e.g., in the protection of plants against pests and pathogens, as well as the medical exploitation of their anti-inflammatory, anticarcinogenic, and antifungal properties, are plausible. The presence of valuable compounds in potato berries could also contribute to the bioeconomy by providing a novel use for otherwise discarded agricultural side streams. Here we review the potential use of these berries for the extraction of compounds that can be exploited to produce pharmaceuticals and plant protection products.

Hibiscus Sabdariffa L. Extract as a Natural Additive in Food Packaging Biodegradable Films to Improve Antioxidant, Antimicrobial, and Physicochemical Properties

In this study, biodegradable active films were prepared from potato starch and polyvinyl alcohol at different proportions, mixed with acetone extract of Hibiscus sabdariffa L. (HS) and using glycerol as a plasticizer. Functional properties, antimicrobial, and antioxidant capacity were evaluated. Potato starch films with a proportion of polyvinyl alcohol up to 50% and HS extract had significant antioxidant capacity and antibacterial effect against most of the analyzed strains. Adding polyvinyl alcohol (PVOH) and HS extract improved the mechanical performance and reduced water vapor permeability of the materials. The active biobased films with HS extract presented good physicochemical, antimicrobial, and antioxidant properties. These materials are considered as suitable for food packaging, and the active compounds in the roselle extract are a natural antibacterial option for the food area. The materials based entirely on biodegradable products are an excellent alternative when developing and marketing biobased materials, minimizing the environmental impact of food packaging.

Functional Food Based on Potato

Potato (Solanum tuberosum L.) has gradually become a stable food worldwide since it can be a practical nutritional supplement and antioxidant as well as an energy provider for human beings. Financially and nutritionally, the cultivation and utility of potatoes is worthy of attention from the world. Exploring the functionality and maximizing the utilization of its component parts as well as developing new products based on the potato is still an ongoing issue. To maximize the benefits of potato and induce new high-value products while avoiding unfavorable properties of the crop has been a growing trend in food and medical areas. This review intends to summarize the factors that influence changes in the key functional components of potatoes and to discuss the focus of referenced literature which may require further research efforts. Next, it summarizes the application of the latest commercial products and potential value of components existing in potato. In particular, there are several main tasks for future potato research: preparing starchy foods for special groups of people and developing fiber-rich products to supply dietary fiber intake, manufacturing bio-friendly and specific design films/coatings in the packaging industry, extracting bioactive proteins and potato protease inhibitors with high biological activity, and continuing to build and examine the health benefits of new commercial products based on potato protein. Notably, preservation methods play a key role in the phytochemical content left in foods, and potato performs superiorly to many common vegetables when meeting the demands of daily mineral intake and alleviating mineral deficiencies.

Content and Stability of Hydroxycinnamic Acids during the Production of French Fries Obtained from Potatoes of Varieties with Light-Yellow, Red and Purple Flesh

Potatoes with different flesh colours contain health-promoting compounds, i.e., hydroxycinnamic acids, which vary in content and stability during thermal processing. The aim of this study was to determine the effect of the technological stages of the production of French fries obtained from potatoes with different flesh colours on the content of selected hydroxycinnamic acids, as well as the stability of these acids, their percentage in sum of acids, total phenolic content and antioxidant activity (ABTS, DPPH) in semi-products and ready-to-eat products. During the production of French fries, samples of unpeeled, peeled, cut, blanched, pre-dried and fried potatoes were collected. After peeling, coloured potatoes, especially purple ones, had more hydroxycinnamic (5-CQA, 4-CQA, 3-CQA and CA) acids remaining in the flesh than in the flesh of the light-yellow variety. The greatest losses of the determined hydroxycinnamic acids, regardless of the given potato's variety, were caused by the stage of pre-drying (about 91%) and frying (about 97%). The French fries obtained from the potatoes with coloured flesh, especially those with purple flesh, had the highest amount of stable 5-CQA and 4-CQA acids as well as 3-CQA acid, already absent in light-yellow French fries. The least stable acid was CA acid, which was not found in any of the ready snacks.

Features and genetic basis of chlorogenic acid formation in diploid potatoes

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A diversity panel of lines was used to study the CGA formation in diploid potatoes.

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Decreased tuber CGA level was observed in the domesticated diploid potatoes.

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Potential factors affecting the CGA level in diploid potatoes were revealed.

The concentration of chlorogenic acids (CGAs), is tightly associated with the appearance, taste, and nutrient content of potato tubers. Manipulation of tuber CGA concentrations allows for the breeding of quality traits in potatoes. Currently, a hybrid potato breeding system that aims to convert tetraploid potato into a diploid seed crop represents a new development in potato breeding. Unfortunately, however, a systematic study of CGA formation is very limited in diploid potatoes. Here, using a diverse panel of diploid potatoes, including 40 ancestors and 374 landraces, we analyzed the influence of location, environment, genetic basis, as well as expression of enzymes, in affecting the CGA concentrations in diploid lines. We revealed a selection of the decreased CGA level of tuber flesh in the domestication of diploid potatoes. Moreover, we identified 18 SNPs associated with tuber CGA levels using re-sequenced genome data. This study provides a basis for the breeding of high-quality potato by taking into consideration customer preferences.

Underutilized Northern plant sources and technological aspects for recovering their polyphenols

Consumers worldwide are increasingly interested in the authenticity and naturalness of products. At the same time, the food, agricultural and forest industries generate large quantities of sidestreams that are not effectively utilized. However, these raw materials are rich and inexpensive sources of bioactive compounds such as polyphenols. The exploitation of these raw materials increases income for producers and processors, while reducing transportation and waste management costs. Many Northern sidestreams and other underutilized raw materials are good sources of polyphenols. These include berry, apple, vegetable, softwood, and rapeseed sidestreams, as well as underutilized algae species. Berry sidestreams are especially good sources of various phenolic compounds. This chapter presents the properties of these raw materials, providing an overview of the techniques for refining these materials into functional polyphenol-rich ingredients. The focus is on economically and environmentally sound technologies suitable for the pre-treatment of the raw materials, the modification and recovery of the polyphenols, as well as the formulation and stabilization of the ingredients. For example, sprouting, fermentation, and enzyme technologies, as well as various traditional and novel extraction methods are discussed. Regarding the extraction technologies, this chapter focuses on safe and green technologies that do not use organic solvents. In addition, formulation and stabilization that aim to protect isolated polyphenols during storage and extend shelflife are reviewed. The formulated polyphenol-rich ingredients produced from underutilized renewable resources could be used as sustainable, active ingredients--for example, in food and nutraceutical industries.

Potato Consumption and Risk of Site-Specific Cancers in Adults: A Systematic Review and Dose-Response Meta-Analysis of Observational Studies

The etiology of cancer type may vary significantly due to anatomy, embryology, and physiology of the cancer site. Although the association between potato consumption and colorectal cancer (CRC) was summarized in a 2018 meta-analysis of 5 cohort studies, to the best of our knowledge, no meta-analysis has evaluated potato consumption in relation to multiple cancer sites in adults. Medline/PubMed, ISI Web of Knowledge, Scopus, and the Cochrane Database of Systematic Reviews were searched for relevant publications through August 2020. We selected cohort or case-control studies conducted in adults that reported risk estimates (relative risk [RRs], HRs, and ORs) of potato intake for any cancer type. Random effects meta-analyses compared high and low intake categories. Twenty prospective cohort studies (total n = 785,348) including 19,882 incident cases, and 36 case-control studies (21,822 cases; 66,502 controls) were included. Among cohort studies, we did not find an association between high versus low intake of total potato (white and yellow) consumption and overall cancers: 1.04 (95% CI: 0.96, 1.11; tau2 = 0.005, n = 18). We found no relation between total potato consumption (high compared with low intake) and risk of CRC, pancreatic cancer, colon, gastric, breast, prostate, kidney, lung, or bladder cancer in cohort or case-control studies. We did not find an association between high versus low consumption of potato preparations (boiled/fried/mashed/roasted/baked) and risk of gastrointestinal-, sex-hormone-, or urinary-related cancers in cohort or case-control studies. Certainty of the evidence was low for total cancer, CRC, colon, rectal, renal, pancreatic, breast, prostate, and lung cancer and very low for gastric and bladder cancer. In conclusion, potato intake or potato preparations were not associated with multiple cancer sites when comparing high and low intake categories. This finding was consistent with the findings from the 2018 meta-analysis regarding potato intake and risk of CRC.

Emerging Processing Technologies for the Recovery of Valuable Bioactive Compounds from Potato Peels

Potato peel (PP) is the major underutilised by-product in the potato-processing industry and a potential source of valuable bioactive molecules. Among them, glycoalkaloids and polyphenols are important precursors for steroid hormones and natural antioxidants, respectively. Moreover, the huge quantities of industrial potato-peel waste that are produced are a rich source of primary metabolites, which principally include starch as well as non-starch polysaccharides, proteins, lipids, lignin and cellulose. All carbohydrates are prone to undergo fermentation to produce ethanol, lactic and acetic acid. Finally, the main portion of PP is made up of alcohol-insoluble matter with a dietary fibre content of approximatively 40%. The present review summarises the recent advances and emerging technologies in potato-peel extraction and further valorisation processing in the food industry.

Biochemical and functional attributes of raw and boiled potato flesh and peel powders for suitability in food applications

Four different potato cultivars, namely, Kufri Chipsona 1 and Kufri Frysona (processing purpose), Kufri Jyoti and Kufri Bahar (table purpose) were converted into flesh and peel powder (raw and after boiling) and studied for their respective biochemical and functional attributes to get an idea of possible dynamics of their utilization in different food formulation as bioadditives. The 16 variants of powder obtained retained less than 10% moisture content and demonstrated 'very good' to 'fair' flowability. Peel powders recorded a higher total mineral, fiber, phenolic contents and total antioxidant activity than the flesh powders which were significantly affected by boiling. Among raw and boiled flesh powders, highest reducing and total sugars were recorded for Kufri Bahar while least was observed in Kufri Chipsona 1. Colour coordinate showed that boiling imparts brightness to flesh powder while peel powder got darkened. Boiling of the tubers resulted in an increase in the resistant starch (~ 29% maximum) and flavour (~ 180% maximum) component. Peel exhibited a total glycoalkaloid content in the range of 0.75 (Kufri Frysona) to 1.7 mg/100 g (Kufri Bahar) that is well within the acceptable limits. Rheological study of the flesh powders revealed a reduction of about 11-18 °C in pasting temperature and about 87-90% in peak viscosity, setback, breakdown value and final viscosity upon boiling. This study revealed that the traditional processing method such as boiling can significantly modify the techno-functional characteristics of potato flesh and peel powders which can further govern their end use in various food formulations.

Characterization of Local Products for Their Industrial Use: The Case of Italian Potato Cultivars Analyzed by Untargeted and Targeted Methodologies

The chemical characterization of local Italian potato cultivars is reported to promote their preservation and use as high quality raw material in food industries. Twenty potato (Solanum tuberosum L.) cultivars from Piedmont and Liguria Italian regions were investigated using NMR (Nuclear Magnetic Resonance) and RP-HPLC-PDA-ESI-MSn (Reversed Phase High-Performance Liquid Chromatography with Photodiode Array Detector and Electrospray Ionization Mass Detector) methodologies. Water soluble and lipophilic metabolites were identified and quantified. With respect to literature data, a more complete ¹H (protonic) spectral assignment of the aqueous potato extracts was reported, whereas the ¹H NMR assignment of potato organic extracts was reported here for the first time. Phenolics resulted to be in high concentrations in the purple–blue colored Rouge des Flandres, Bergerac, Fleur Bleu, and Blue Star cultivars. Servane, Piatlina, and Malou showed the highest amount of galacturonic acid, a marker of pectin presence, whereas Jelly cultivar was characterized by high levels of monosaccharides. Roseval and Rubra Spes contained high levels of citric acid involved in the inhibition of the enzymatic browning in fresh-cut potato. High levels of the amino acids involved in the formation of pleasant-smell volatile compounds during potato cooking were detected in Rouge des Flandres, Blue Star, Bergerac, Roseval, and Ratte cultivars. These results suggest that each local cultivar is characterized by a proper chemical profile related to specific proprieties that can be useful to obtain high quality industrial products.

Exploring the relationship between potato components and Maillard reaction derivative harmful products using multivariate statistical analysis

The correlation between potato components and Maillard reaction derivative harmful products (MRDHPs) formation during heat-processing was assessed in nine commercial potato varieties in China. Principal component analysis (PCA) combined with canonical correlation analysis (CCA) approach was performed to explore their relationships. The variables contributing most to the PCA results were extracted for CCA, and the results indicated that several amino acids, including lysine, tryptophan, alanine, phenylalanine, aspartate, and glutamate, have significant impacts on acrylamide and β-carboline heterocyclic amine formation. Moreover, 5-O-caffeoylquinic acid, 3-O-caffeoylquinic acid, α-solanine, and α-chaconine were also important factors associated with acrylamide and β-carboline heterocyclic amine formation. Optimally using raw potato varieties based on the impacts of these factors can help control MRDHP formation during thermal processing. For the first time, such approach was applied, which may be a useful tool for discovering the correlation of food components and MRDHPs.

Dietary Phenolic Acids and Flavonoids as Potential Anti-Cancer Agents: Current State of the Art and Future Perspectives

Background:

Cancer is a rapidly growing disease and the second most leading cause of death worldwide. Breast, colon, lung, and prostate cancer are the most diagnosed types of cancer among the majority of the population. The prevalence of these cancers is increasing rapidly due to the lack of effective drugs. The search for anti-cancer bioactive components from natural plant sources is gaining immense significance. The aim of the paper is to introduce the readers about the in vitro and in vivo biochemical mechanisms of phenolic acids and flavonoids in these four types of cancers.

Methods:

A literature search was carried out in databases, including Scopus, SciFinder, Springer, Science direct and Google. The main keywords used were fruits & vegetables, phenolic acids, flavonoids, anticancer, bioavailability, etc. The data obtained were integrated and analyzed.

Results:

The study revealed the potential molecular mechanisms of phenolic acids and flavonoids, which include the induction of apoptosis, inhibition of cell proliferation, cell-cycle arrest, induction of Poly ADP ribose polymerase cleavage, downregulation of Matrix metalloproteinases-2 and Matrix metalloproteinases-9 activities, decreased levels of B-cell lymphoma-2, etc. Promising effects of phenolic acids and flavonoids have been observed against breast, colon, lung and prostate cancers.

Conclusion:

The in vitro and in vivo anti-cancer mechanisms of phenolic acids and flavonoids have been revealed in this study. With the knowledge of specific molecular targets and the structural-functional relationship of bioactive compounds, the current review will open a new gateway for the scientific community and provide them a viable option to exploit more of these compounds for the development of novel and efficacious anticancer compounds.

Characterisation and antioxidant activity of sohphlang (Flemingia vestita), a tuberous crop

This study aimed to assess the nutritional and antioxidant properties of sohphlang (Flemingia vestita), a tuber that is traditionally consumed in raw form in Meghalaya, a North-Eastern state of India. Cultivated sohphlang (CS) and market sohphlang (MS) flours were analysed for nutrient composition. The extracts of the flours from conventional-assisted-extraction (CAE), microwave-assisted-extraction (MAE) and ultrasound-assisted-extraction (UAE) were analysed for total phenolic content (TPC), total flavonoid content (TFC) and antioxidant activities (AA). CS flour exhibited good nutritional properties, TPC, TFC and AA than MS flour. Furthermore, MAE gave better extraction efficiency than UAE and CAE. HPLC results showed genistein as the predominant compound among the phenolic compounds identified that is comparable with soybean. Thus, tuber sohphlang that is eaten in raw form can serve as a versatile source of food and nutritional security to the people. The tuber also offers scope for exploiting its health benefitting functional ingredients.

The Effect of High Pressure Processing on Polyphenol Oxidase Activity, Phytochemicals and Proximate Composition of Irish Potato Cultivars

Polyphenol oxidase (PPO) activity, proximate composition, and phytochemicals were determined in four common Irish potato cultivars following a high pressure processing (HPP) at 600 MPa for 3 min. PPO activity was significantly (p < 0.05) lower in all HPP treated samples, while the overall proximate composition was not affected. The total phenolic content was significantly higher in the HPP treated samples. Chlorogenic acid levels significantly decreased with simultaneous increase of caffeic acid and p-coumaric acid levels upon HPP treatment. No significant changes were observed in rutin and ferulic acid levels, although their levels varied, depending on the potato cultivars, while the levels of cytotoxic glycoalkaloids (α-solanine and α-chaconine) remained unaltered.

Phenolic Compounds and Antioxidant Activities of Potato Cultivars with White, Yellow, Red and Purple Flesh

The contents of total phenolics (TPC), individual phenolic acid and antioxidant activities in the free and bound fractions of potato with different flesh colors were systematically investigated. The TPC and antioxidant capacity in the bound fraction was significantly lower than that in the free fraction. Chlorogenic acid, neochlorogenic acid, cryptochlorogenic acid, caffeic acid, p-coumaric acid and ferulic acid were detected in the free fraction with chlorogenic acid being the most predominant, accounting for 35.21-81.78% of the total content. Caffeic acid, p-coumaric acid and ferulic acid were detected in the bound fraction in the colored potato with caffeic acid being the major one. In the free fraction, the content of each individual phenolic acid had positive correlation with antioxidant activity. In the bound fraction, caffeic acid and p-coumaric acid showed positive correlation with antioxidant activity. This study promotes further understanding of the correlations among TPC, phenolic acids and antioxidant activity.

Acrylamide Content of Experimental Flatbreads Prepared from Potato, Quinoa, and Wheat Flours with Added Fruit and Vegetable Peels and Mushroom Powders

Flatbreads are a major food consumed worldwide. To mitigate an undesirable safety aspect of flatbreads that might be associated with the potentially-toxic compound acrylamide, we recently developed recipes using a variety of grains that resulted in the production of low-acrylamide flatbreads. To further enhance the functionality of flatbreads, we have developed, in this work, new experimental flatbreads using potato, quinoa, and wheat flours supplemented with peel powders prepared from commercial nonorganic and organic fruits and vegetables (apples, cherry tomatoes, melons, oranges, pepino melons, sweet potato yams), potato peels, and mushroom powders (Lion’s Mane, Hericium erinaceus; Reishi, Ganoderma lucidum; and Turkey Tail, Trametes versicolor). These additives have all been reported to contain beneficial compositional and health properties. The results of fortification of the baked flatbreads showed either no effect or increases in acrylamide content by unknown mechanisms. Since the additives did not increase the acrylamide content of the quinoa flour flatbreads for the most part, such supplemented quinoa flatbreads have the potential to serve as a nutritional, gluten-free, low-acrylamide, health-promoting functional food. Mushroom powder-fortified wheat flatbreads with relatively low acrylamide content may also have health benefits.

Biomarkers of tuber intake

Tubers are important crops as well as staple foods in human nutrition. Among tubers, the potato in particular has been investigated for its health effects. However, except for its contribution to energy and effects related to resistant starch, the role of potatoes and other tubers in human health is still debated. In order to establish firm evidence for the health effects of dietary tubers and processed tuber products, it is essential to assess total intake accurately. The dietary assessment in most studies relies mainly on self-reporting and may give imprecise quantitative information on dietary intakes. Biomarkers of food intake (BFIs) are useful objective means to assess intake of specific foods or may be used as an additional measure to calibrate the measurement error in dietary reports. Here, intake biomarkers for common tubers, including potatoes and heated potato products, sweet potato, cassava, yam, and Jerusalem artichoke, are reviewed according to the biomarker of food intake reviews (BFIRev) standardized protocols for review and validation. Candidate BFIs for heated potato product include α-chaconine, α-solanine, and solanidine; less evidence is available to indicate peonidin 3-caffeoylsophoroside-5-glucoside and cyanidin 3-caffeoylsophoroside-5-glucoside as putative biomarkers having high potential specificity for purple sweet potato intake; linamarin may in addition be considered as a putative BFI for cassava. Other tubers also contain toxic glycosides or common contaminants as characteristic components but their putative use as intake biomarkers is not well documented. Alkyl pyrazines, acrylamide, and acrolein are formed during cooking of heated potato products while these have not yet been investigated for other tubers; these markers may not be specific only to heated potato but measurements of these compounds in blood or urine may be combined with more specific markers of the heated products, e.g., with glycoalkaloids to assess heated potato products consumption. Further studies are needed to assess the specificity, robustness, reliability, and analytical performance for the candidate tuber intake biomarkers identified in this review.

Metabolic diversity in tuber tissues of native Chiloé potatoes and commercial cultivars of Solanum tuberosum ssp. tuberosum L

INTRODUCTION

The native potatoes (Solanum tuberosum ssp. tuberosum L.) cultivated on Chiloé Island in southern Chile have great variability in terms of tuber shape, size, color and flavor. These traits have been preserved throughout generations due to the geographical position of Chiloé, as well as the different uses given by local farmers.

OBJECTIVES

The present study aimed to investigate the diversity of metabolites in skin and pulp tissues of eleven native accessions of potatoes from Chile, and evaluate the metabolite associations between tuber tissues.

METHODS

For a deeper characterization of these accessions, we performed a comprehensive metabolic study in skin and pulp tissues of tubers, 3 months after harvesting. Specific targeted quantification of metabolites using 96 well microplates, and high-performance liquid chromatography combined with non-targeted metabolite profiling by gas chromatography time-of-flight mass spectrometry were used in this study.

RESULTS

We observed differential levels of antioxidant activity and phenolic compounds between skin and pulp compared to a common commercial cultivar (Desireé). In addition, we uncovered considerable metabolite variability between different tuber tissues and between native potatoes. Network correlation analysis revealed different metabolite associations among tuber tissues that indicate distinct associations between primary metabolite and anthocyanin levels, and antioxidant activity in skin and pulp tissues. Moreover, multivariate analysis lead to the grouping of native and commercial cultivars based on metabolites from both skin and pulp tissues.

CONCLUSIONS

As well as providing important information to potato producers and breeding programs on the levels of health relevant phytochemicals and other abundant metabolites such as starch, proteins and amino acids, this study highlights the associations of different metabolites in tuber skins and pulp, indicating the need for distinct strategies for metabolic engineering in these tissues. Furthermore, this study shows that native Chilean potato accessions have great potential as a natural source of phytochemicals.

Comprehensive metabolite profiling of Solanum tuberosum L. (potato) leaves by HPLC-ESI-QTOF-MS

The objective of this work was to study the non-targeted metabolite profiling of potato leaves using high performance liquid chromatography coupled to quadrupole-time of flight mass spectrometry (HPLC-ESI-QTOF-MS). The mass accuracy, true isotopic pattern in both MS and MS/MS spectra provided by QTOF-MS made possible the tentative identification of 109 compounds present in potato leaves, including organic acids, amino acids and derivatives, phenolic acids, flavonoids, iridoids, oxylipins and other polar and semi-polar compounds. Among them, 32 compounds have been found for the first time in potato leaf and in the Solanaceae family. Quinic acid and its derivatives represented more than 45% of the bioactive compounds quantified in the extract. Derivatives of hydroxybenzoic acid and gentisic acid were also founded at considerable concentrations. This study shed light on the composition of potato leaf extract and will serve as a base for further research into activities of the various compounds found in this matrix which has demonstrated a potential use as functional ingredients.

Bactericidal and Cytotoxic Activities of Polyphenol Extracts from Solanum tuberosum spp. tuberosum and spp. andigena Cultivars on Escherichia coli and Human Neuroblastoma SH-SY5Y Cells In Vitro

Potatoes (Solanum tuberosum L.) are a good source of dietary antioxidant polyphenols. This study investigated the potential antioxidant, bactericidal, and cytotoxic activities in vitro of the phenolic compounds present in tubers of one S. tuberosum spp. tuberosum (Summerside), and three S. tuberosum spp. andigena (landraces Moradita, Waicha, and Santa María) cultivars. Both the content of phenolic acids, chlorogenic acids (CGAs) being the most abundant, and the antioxidant activity were higher in extracts from skin than from flesh. Extracts from Moradita flesh and Summerside skin showed bactericidal activity against Escherichia coli ATCC 25922 but failed to inhibit pathogenic E. coli O157. Both extracts lack pigmentation but do contain 5-CGA, caffeic, and ferulic acids. Positive control with gentamicin and commercial 5-CGA resulted in a complete inhibition of bacterial growth. In addition, all potato extracts and commercial 5-CGA diminished dose-dependently human neuroblastoma SH-SY5Y cell viability. Skin extracts were more potent than flesh extracts. Among flesh extracts, Moradita was the most potent. Together, our results suggest that Moradita flesh could provide a desirable source of important health-promoting substances. Findings indicate that the biological activity of potato extracts is a combination of various bioactive compounds and contribute to the revalorization of potato as a functional food.

Optimization of Conditions for Extraction of Polyphenols and the Determination of the Impact of Cooking on Total Polyphenolic, Antioxidant, and Anticholinesterase Activities of Potato

In this work we optimized the cooking and extraction conditions for obtaining high yields of total polyphenols from potato and studied the effect of three domestic methods of cooking on total phenols, antioxidant activity, and anticholinesterase activities. The optimization of the experiment was carried out by the experimental designs. The extraction of the polyphenols was carried out by maceration and ultrasonication. Determination of the polyphenols was performed by using the Folin-Ciocalteau reagent method. The antioxidant activity was evaluated by three methods: 1,1-diphenyl-2-picryl-hydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), and CUPRAC(Cupric reducing antioxidant capacity), the anticholinesterase activity was evaluated by the method of Elmann. The optimum of total phenolic obtained was: 4.668 × 10⁴, 1.406 × 10⁴, 3357.009, 16,208.99 µg Gallic Acid Equivalent (GAE)/g of dry extract for crude potato, steamed potatoes, in boiling water, and by microwave, respectively. The three modes of cooking cause a decrease in the total polyphenol contents, antioxidant and anticholinesterase activities.

Hydroxycinnamic acids in cooked potato tubers from Solanum tuberosum group Phureja

Hydroxycinnamic acids are phenolic compounds and are considered to have health promotion properties due to their antioxidant activity. Potato tubers of 113 genotypes of Solanum tuberosum group Phureja belonging to the Colombian Central Collection, landraces of potatoes, and commercial cultivars were evaluated for their hydroxycinnamic acids content. The composition of these compounds was analyzed using cooked tubers in two different agro-climatic conditions. The genotypes were analyzed for chlorogenic acid, neo-chlorogenic acid, crypto-chlorogenic acid, and caffeic acid by ultrahigh-performance liquid chromatography (UHPLC). Chlorogenic acid was the major representative and varied between 0.77 to 7.98 g kg-1 DW (dry weight) followed by crypto-chlorogenic acid (from 0.09 to 1.50 g kg-1 DW). Under moorland agro-climatic conditions even though the chlorogenic acid levels increased with respect to flatland agro-climatic conditions, the related isomer neo-chlorogenic acid decreased as compared to flatland conditions. The correlation between chlorogenic acid with the isomers, and with caffeic acid was positive. This study demonstrated that there is a wide variation in hydroxycinnamic acids contents in the germplasm studied, which can be exploited in breeding programs to contribute to human health.

Phenolic Compounds in the Potato and Its Byproducts: An Overview

The potato (Solanum tuberosum L.) is a tuber that is largely used for food and is a source of different bioactive compounds such as starch, dietary fiber, amino acids, minerals, vitamins, and phenolic compounds. Phenolic compounds are synthetized by the potato plant as a protection response from bacteria, fungi, viruses, and insects. Several works showed that these potato compounds exhibited health-promoting effects in humans. However, the use of the potato in the food industry submits this vegetable to different processes that can alter the phenolic content. Moreover, many of these compounds with high bioactivity are located in the potato's skin, and so are eliminated as waste. In this review the most recent articles dealing with phenolic compounds in the potato and potato byproducts, along with the effects of harvesting, post-harvest, and technological processes, have been reviewed. Briefly, the phenolic composition, main extraction, and determination methods have been described. In addition, the "alternative" food uses and healthy properties of potato phenolic compounds have been addressed.

Cognitive and neuroprotective effects of chlorogenic acid

OBJECTIVES

The aim of this review was to provide an overview of studies conducted to determine the effects of chlorogenic acid (CGA) on cognition and neurological health.

METHODS

A literature search was conducted using PubMed and various search terms including chlorogenic acid, CGA, memory, neuroscience, cognition, nutrition, antioxidant, pharmacokinetics, neuroprotection, and neurodegeneration.

RESULTS

Many studies have linked CGA consumption to a wide range of health benefits, including neuroprotection, cardioprotection, weight loss, chemopreventive properties, anti-inflammatory activity, decreased blood pressure, decreased diet-induced insulin resistance, decreased blood pressure, anxiolytic effects, and antihyperalgesic effects. Pre-clinical and clinical studies both provide evidence that CGA supplementation could protect against neurological degeneration and the resulting diseases associated with oxidative stress in the brain; however, no formal, well-controlled studies have been performed to date.

DISCUSSION

Recent research suggests that dietary consumption of CGA could produce a wide range of health benefits and physiological effects. There is also mounting evidence that the consumption of polyphenols, including CGA, in the diet could reduce the risk of developing neurodegenerative conditions. Further studies should be conducted with a focus on the effects of CGA on cognition and the nervous system and employing well-designed clinical studies.

Chlorogenic Acid Biosynthesis Appears Linked with Suberin Production in Potato Tuber (Solanum tuberosum)

Potato (Solanum tuberosum L.) is a good source of dietary antioxidants. Chlorogenic acid (CGA) and caffeic acid (CA) are the most abundant phenolic acid antioxidants in potato and are formed by the phenylpropanoid pathway. A number of CGA biosynthetic routes that involve hydroxycinnamoyl-CoA quinate hydroxycinnamoyl transferase (HQT) and/or hydroxycinnamoyl-CoA shikimate/quinate hydroxycinnamoyl transferase (HCT) have been proposed, but little is known about their path in potato. CA production requires a caffeoyl shikimate esterase (CSE), and CA serves as a substrate of lignin precursor ferulic acid via the action of caffeic/5-hydroxyferulic acid O-methyltransferase (COMT I). CGA is precursor of caffeoyl-CoA and, via caffeoyl-CoA O-methyltransferase (CCoAOMT), of feruloyl-CoA. Feruloyl-CoA is required for lignin and suberin biosynthesis, crucial for tuber development. Here, metabolite and transcript levels of the mentioned and related enzymes, such as cinnamate 4-hydroxylase (C4H), were determined in the flesh and skin of fresh and stored tubers. Metabolite and transcript levels were higher in skin than in flesh, irrespective of storage. CGA and CA production appear to occur via p-coumaroyl-CoA, using HQT and CSE, respectively. HCT is likely involved in CGA remobilization toward suberin. The strong correlation between CGA and CA, the correspondence with C4H, HQT, CCoAOMT2, and CSE, and the negative correlation of HCT and COMT I in potato tubers suggest a major flux toward suberin.

Protective effect of a hydroethanolic extract from Bowdichia virgilioides on muscular damage and oxidative stress caused by strenuous resistance training in rats

Background

Natural antioxidants can reduce oxidative damage caused by high-intensity resistance training (RT). We investigated the in vitro antioxidant potential of hydroethanolic extract (HEE) from Bowdichia virgilioides on muscular damage and oxidative stress in rats subjected to high-intensity RT.

Methods

Thirty-two male Wistar rats were divided into four experimental groups: 1) control group (CG), oral administration (P.O.) of vehicle; 2) trained group (TG), vehicle-treated with RT; 3) B. virgilioides untrained group (BVG), treated with B. virgilioides HEE (200 mg/kg P.O.); and 4) trained B. virgilioides group (TBVG), treated with B. virgiliodes HEE (200 mg/kg P.O.). All animals were habituated to the training apparatus for 1 week. CT and TBVG animals were subjected to the training protocol, which consisted of three sets of 10 repetitions with 75% of the load established using the one-repetition maximum, for four weeks. CG and BVG animals were manipulated and fixed to the apparatus three times a week with no load. Treatment with B. virgilioides HEE or vehicle treatment was initiated after 25 days of RT (5 days; one dose per day). At the end of the experiments, plasmatic and gastrocnemius samples from all groups were obtained for the assessment of lipid peroxidation and creatine kinase activity.

Results

Compared to TG rats, TBVG rats showed decreases in plasma and gastrocnemius tissue lipid peroxidation by 55.68% (p <0.0001) and 66.61% (p <0.0012), respectively. Further, compared to TG rats TBVG rats showed decreases in plasma and gastrocnemius tissue oxidative stress by 62.83% (p <0.0005) and 54.97% (p <0.0197), respectively.

Conclusions

B. virgilioides HEE treatment reduced markers of oxidative stress caused by high-intensity RT. Further, HEE treatment during training significantly reduced the markers of tissue damage.

Phenolic characterization and variability in leaves, stems and roots of Micro-Tom and patio tomatoes, in response to nitrogen limitation

Phenolics are implicated in the defence strategies of many plant species rendering their concentration increase of putative practical interest in the field of crop protection. Little attention has been given to the nature, concentration and distribution of phenolics within vegetative organs of tomato (Solanum lycopersicum. L) as compared to fruits. In this study, we extensively characterized the phenolics in leaves, stems and roots of nine tomato cultivars using high-performance liquid chromatography coupled to electrospray ionization tandem mass spectrometry (LC-MS(n)) and assessed the impact of low nitrogen (LN) availability on their accumulation. Thirty-one phenolics from the four sub-classes, hydroxycinnamoyl esters, flavonoids, anthocyanins and phenolamides were identified, five of which had not previously been reported in these tomato organs. A higher diversity and concentration of phenolics was found in leaves than in stems and roots. The qualitative distribution of these compounds between plant organs was similar for the nine cultivars with the exception of Micro-Tom because of its significantly higher phenolic concentrations in leaves and stems as compared to roots. With few exceptions, the influence of the LN treatment on the three organs of all cultivars was to increase the concentrations of hydroxycinnamoyl esters, flavonoids and anthocyanins and to decrease those of phenolamides. This impact of LN was greater in roots than in leaves and stems. Nitrogen nutrition thus appears as a means of modulating the concentration and composition of organ phenolics and their distribution within the whole plant.

Characterization and quantitation of anthocyanins and other phenolics in native Andean potatoes

Andean potatoes are gaining popularity not only for their appealing colors and culinary uses but also for their potential higher content of polyphenolic compounds. The objective of this study was to identify potato varieties with increased phenolic content. This was achieved through characterization and quantitation of the phenolic composition in 20 varieties of native Andean potatoes from 4 different Solanum species with different colors. Major quantitative and qualitative differences among evaluated samples were more dependent on the coloration of the extracted sample rather than on the species. The most predominant anthocyanidins were petunidin-3-coumaroylrutinoside-5-glucoside and pelargonidin-3-coumaroylrutinoside-5-glucoside in purple and red potato extracts, respectively, while chlorogenic acid and its isomers were the main phenolic compund (43% of the total phenolic content). Our study suggested that the appropriate selection of native potatoes could provide new sources of polyphenolics with health promoting properties and natural pigments with increased stability for food applications.

Effect of farming systems on the yield, quality parameters and sensory properties of conventionally and organically grown potato (Solanum tuberosum L.) tubers

The objectives of this two-year research were to study the impact of two different farming types, conventional and organic, on the yield and sensory properties of five Lithuanian varieties of potato tuber. The parameters and properties examined were: phenolic acids; dry matter and starch content; and the spread and intensity of Phytophthora infestans growth. It was determined that potato yield fluctuates with the variety, but for conventional farming it is significantly (p<0.05) higher than that obtained by organic farming. The farming type has no significant effect (p>0.05) on the content of phenolic acids. No significant effect (p>0.05) of farming type on dry matter and starch content, or sensory properties was found. No significant relation (p>0.05) was found between the content of phenolic acids and P. infestans spread. The spread of P. infestans was faster and infection was heavier in organically grown potatoes.

Combined effects of storage and processing on the bioactive compounds and pro-apoptotic properties of color-fleshed potatoes in human colon cancer cells

Potatoes can be stored for up to 1 year before being processed and consumed. The objective of this study was to determine the extent to which fresh and stored color-fleshed potatoes retain their anticancer properties after baking and chipping compared with unprocessed potatoes. We utilized white-, yellow-, and purple-fleshed potato clones and tested their phenolic and anthocyanin content, antioxidant activity, metabolite profile, and antiproliferative and pro-apoptotic properties. When compared with unprocessed samples, baking or chipping led to significant losses in the phenolic and anthocyanin content and antioxidant activity of the potatoes. However, with storage, total phenolic and anthocyanin content and antioxidant activity increased in baked samples while in the chipped samples they remained constant. Ethanolic extracts of baked and chipped samples suppressed proliferation and elevated apoptosis (p < 0.05) in HCT-116 (p53 wild-type; ras mutated) and HT-29 (p53 mutated; ras wild-type) human colon cancer cell lines. Antiproliferative and pro-apoptotic properties of baked potatoes were similar to that of fresh potatoes, while chipping caused a significant suppression. Phenolic content and antioxidant activity of purple-fleshed potatoes, after baking, were comparable with those of anthocyanin-rich berries. Hence, purple-fleshed potatoes can be a healthier choice for consumers as they possess greater levels of bioactive compounds and anticancer properties even after processing as compared with their white- and yellow-fleshed counterparts.