Purple Potato Research Articles

1H NMR Metabolomics and Full-Length RNA-Seq Reveal Effects of Acylated and Nonacylated Anthocyanins on Hepatic Metabolites and Gene Expression in Zucker Diabetic Fatty Rats.

Anthocyanins have been reported to possess antidiabetic effects. Recent studies indicate acylated anthocyanins have better stability and antioxidative activity compared to their nonacylated counterparts. This study compared the effects of nonacylated and acylated anthocyanins on hepatic gene expression and metabolic profile in diabetic rats, using full-length transcriptomics and 1H NMR metabolomics. Zucker diabetic fatty (ZDF) rats were fed with nonacylated anthocyanin extract from bilberries (NAAB) or acylated anthocyanin extract from purple potatoes (AAPP) at daily doses of 25 and 50 mg/kg body weight for 8 weeks. Both anthocyanin extracts restored the levels of multiple metabolites (glucose, lactate, alanine, and pyruvate) and expression of genes (G6pac, Pck1, Pklr, and Gck) involved in glycolysis and gluconeogenesis. AAPP decreased the hepatic glutamine level. NAAB regulated the expression of Mgat4a, Gstm6, and Lpl, whereas AAPP modified the expression of Mgat4a, Jun, Fos, and Egr1. This study indicated different effects of AAPP and NAAB on the hepatic transcriptomic and metabolic profiles of diabetic rats.

Phenolic Metabolites in the Urine and Plasma of Healthy Men After Acute Intake of Purple Potato Extract Rich in Methoxysubstituted Monoacylated Anthocyanins

Structurally stable acylated anthocyanins have potential in various food applications but the effects of acylation and methoxysubstitution on anthocyanin metabolism are poorly understood. This is the first study thoroughly investigating phenolic metabolites, their time-wise changes, and pharmacokinetics following an acute intake of methoxysubstituted monoacylated anthocyanins. Healthy male volunteers (n = 17) consumed a yellow potato meal with and without purple potato extract rich in acylated anthocyanins (152mg) and hydroxycinnamic acid conjugates (140mg). Ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) is used for identification and quantification of metabolites from serially collected urine and plasma. While the parent anthocyanins are not detected, 28 phenolic metabolites from urine and 14 from plasma are quantified, including hydroxybenzoic and hydroxycinnamic acids and protocatechuic acid sulfates and glucuronides; three (catechol, gallic acid-4-O-glucuronide, and 2-methoxybenzoic acid) are detected for the first time after anthocyanin-rich food. Urinary hippuric acid is the most abundant with an increase of 139µM mM-1 creatinine after the treatment. A large additional set of tentatively identified phenolic metabolites are detected. Late urinary peak time values suggest colonic degradation. Acylated anthocyanins are more bioavailable than earlier reported after extensive degradation in human and/or colonial metabolism to phenolic metabolites, which may be further conjugated and demethylated.

Anthocyanin-containing purple potatoes ameliorate DSS-induced colitis in mice

Ulcerative colitis (UC), a major form of inflammatory bowel disease (IBD), is on the rise worldwide. Approximately three million people suffer from IBD in the United States alone, but the current therapeutic options (e.g., corticosteroids) come with adverse side effects including reduced ability to fight infections. Thus, there is a critical need for developing effective, safe and evidence-based food products with anti-inflammatory activity. This study evaluated the antiinflammatory potential of purple-fleshed potato using a dextran sodium sulfate (DSS) murine model of colitis. Mice were randomly assigned to control (AIN-93G diet), P15 (15% purple-fleshed potato diet) and P25 (25% purple-fleshed potato diet) groups. Colitis was induced by 2% DSS administration in drinking water for six days. The results indicated that purple-fleshed potato supplementation suppressed the DSS-induced reduction in body weight and colon length as well as the increase in spleen and liver weights. P15 and P25 diets suppressed the elevation in the intestinal permeability, colonic MPO activity, mRNA expression and protein levels of pro-inflammatory interleukins IL-6 and IL-17, the relative abundance of specific pathogenic bacteria such as Enterobacteriaceae, Escherichia coli (E. coli) and pks+ E. coli, and the increased flagellin levels induced by DSS treatment. P25 alone suppressed the elevated systemic MPO levels in DSS-exposed mice, and elevated the relative abundance of Akkermansia muciniphila (A. muciniphila) as well as attenuated colonic mRNA expression level of IL-17 and the protein levels of IL-6 and IL-1β. Therefore, the purple-fleshed potato has the potential to aid in the amelioration of UC symptoms.

Oxidative stability of high oleic sunflower oil during deep-frying process of purple potato Purple Majesty

The behaviour of high oleic sunflower oil in deep frying process of purple potato Purple Majesty has been evaluated simulating a fast food cooking process. This oil was used for 8h/day for 6 days, filling up from the 2nd day. A discontinuous and prolonged procedure was tested. Free Fatty Acidity (FFA), Peroxide Value (PV), Total Polar Compounds (TPC), Fatty Acid (FA) composition, Volatile Organic Compounds (VOC) have been determined at different times in thermo-oxidized (T-OX) oil, and in frying oil. The FFA in T-OX oil samples showed values in the range 0.09%–0.24%, whereas in the frying oil values varied in a range between 0.09% and 0.16%. TPCs values varied from 1.76% to 38.24% in T-OX oils, whereas in frying oil used for frying purple potatoes (FOPP) showed values in the range from 1.76 to 29.13%. The peroxides values did not follow a regular pattern, both during thermo-oxidation and during frying. Among the Long Chain Fatty Acids (LCFAs), oleic acid was the most represented (84.13%). Short chain fatty acids (SCFAs) amount was 0.34% (octanoic acid). Medium chain fatty acids (MCFA) amount was 4.45% (palmitic acid). During the thermo-oxidation, the poly-unsaturated fatty acids (PUFA) amount decreased during the 48 h of heat treatment, reaching an amount of 6.21%. This determined the increase in short chain fatty acids (SCFA). Trans fatty acids increased with the frying time. Unsaturated fatty acids (UFA) reached the value of 90.19%; SFA was 9.79%, and octanoic acid was 0.20%. A correlation between TPC vs UFA/SFA and TPC vs C18:2/C16:0 was observed in the frying oil. The most abundant volatile compounds in frying oil (from 0 to 48 h) were the aldehydes produced by decomposition of hydroperoxides of oleic and linoleic acids.

PH-sensitive and antibacterial films developed by incorporating anthocyanins extracted from purple potato or roselle into chitosan/polyvinyl alcohol/nano-ZnO matrix: Comparative study

pH-sensitive and antibacterial films based on chitosan/polyvinyl alcohol/nano-ZnO (CPZ) containing anthocyanins extracted from purple potato (PPE) or roselle (RE) were developed. When incorporated with PPE or RE, the moisture contents and flexibility of film significantly reduced (P < 0.05), while mechanical resistance of film was significantly enhanced (P < 0.05). Water vapor permeability (WVP) of film was slightly influenced by the addition of PPE or RE (P > 0.05). CPZ-RE film exhibited darker color and lower light transmittance than CPZ-PPE film at the same incorporation level. CPZ-PPE and CPZ-RE films exhibited distinguishable color changes in different pH buffer solutions. CPZ-PPE films exhibited higher antibacterial activity against Escherichia coli and Staphylococcus aureus than CPZ-RE films. Moreover, film could effectively monitor spoilage degree of shrimp when film changed from purple to light-green. Our results suggested CPZ-PPE and CPZ-RE films have promising potential as active and smart packaging materials for applications in food industry.

Development and characterisation of gluten‐free potato bread

SummaryThe aim of this study was to develop a novel and entirely potato‐based staple bread. Bread‐making performance of individual potato components (starch, protein and fibre) were independently evaluated and optimised by their ternary mixture. Flours from yellow and purple potatoes were then incorporated up to 25% of full formula weight to maximise the utilisation of resources. Fresh tuber was further added up to 50% for the full benefits from potatoes. The excessive oven‐rising after the crust hardened was manipulated by delicately balancing the strong swelling power of potato starch, which effectively resolved the cracks on the crust. The resultant potato breads showed a typical bread appearance, loaf size, low porosity but high cell density crumb structure and unique favourable sensory qualities, especially those with 2% potato fibre or 30% fresh tuber. Potato breads staled quickly during storage, but reheating could reverse the bread staleness to a nearly freshly baked state.

Some regularities in the process of anthocyanin extraction from vegetable sources

This work investigates regularities in the process of extracting anthocyanins from various plant sources in the medium of extractants. For extraction, fresh plant samples were used, including the roots of purple carrots, roots of purple potatoes of the Amethyst variety, fresh fruits of Michurin's aronia, fruits of the garden nightshade, cornelian cherries, blueberries and red cabbage, as well as dried peony petals. The extraction was carried out by infusing the plant material under study in a selected extractant (left overnight). The concentration of anthocyanins was determined spectrophotometrically. It was shown that a 0.1 M aqueous solution of HCl is an effective and environmentally friendly extractant allowing for the extraction of anthocyanins from various sources. Provided that the medium acidity is greater than 1, significant losses of anthocyanins are possible: 5-45% at pH = 2; 33-88% at pH = 3; 41-92% when extracted with distilled water. Acylation does not contribute to an increase in the degree of anthocyanin extraction. The addition of organic solvents (ethanol, acetonitrile and glycerin) can significantly accelerate the anthocyanin extraction in some cases, which is particularly true for cornelian cherries. When using crushed material, the influence of the extractant on the degree of extraction is minimal. Information is presented on the solvatochromic effect, which affects the spectral characteristics of some anthocyanin solutions. It was shown that the shift of the absorption band maximum is the greatest for non-acylated anthocyanins, while decreasing for acylated compounds. The latter is most likely to be associated with the intramolecular copigmentation of acylated anthocyanins in aqueous solutions. When determining the concentration of anthocyanins in solvents with different concentrations of organic additives, the solvatochromic effect should be taken into account. The addition of an organic solvent leads not only to a shift in the absorption band maxima, but also to significant hyperchromic effects. If this effect is ignored, errors in determination of anthocyanins can exceed 70%. This paper proposes a simple and effective approach to considering these effects using a cross-dilution scheme. Therefore, the choice of extractants for efficient anthocyanin extraction from various plant raw materials was experimentally substantiated, and a method for evaluating solvatochromic effects was proposed.

Content determination of functional composition and antioxidant activity from six purple plants

Background: Nowadays, many purple vegetables are available in the market. These vegetables have rich content of anthocyanins, which gives them their characteristic purple color. A high intake of anthocyanin-rich vegetables/plant parts imparts potential beneficial effects. Therefore, in this study, we investigated six purple plants (SPPs; purple cauliflower, purple potato, purple lettuce, purple carrot, purple beans, and purple tomato) for their content of functional composition and their antioxidant activity. Materials and Methods: Anthocyanins from SPPs were extracted and purified by an optimized process. Then, we determined the total anthocyanin (TA) and cyanidin-3-O-glucoside (C-3-G) content in the anthocyanin purified extracts (APEs) from the SPPs through pH difference and high-performance liquid chromatographic methods, respectively. 2,2-diphenyl-1-picrylhydrazyl and ferric reducing antioxidant power methods were used to test the antioxidant activities of the APEs. In addition, the contents of the total flavonoids, total polyphenol, Vitamin C, and dietary fiber from the SPPs were determined. Results: SPPs are rich in anthocyanins, flavonoids, phenolic acids, and other compounds that show strong antioxidant activity. According to our results, anthocyanin content was the highest in purple cauliflower, which translated into the greatest antioxidant activity of the APEs of purple cauliflower. The content of total flavonoid, polyphenol, and Vitamin C in the purple lettuce was higher than that of the other plants. The highest content of dietary fiber was found in purple potato. Conclusion: According to our results, purple cauliflower is the most potential plants to the pharmaceutical industry. Our results provide a theoretical basis for further exploration of efficacy of the purple plants and exploitation.

Antitumor and antioxidant activities of purple potato ethanolic extract and its interaction with liposomes, albumin and plasmid DNA.

The aim of the study was to broadly determine the biological activities of purple potato ethanolic extract of the Blue Congo variety (BCE). The antioxidant activity of BCE was determined in relation to liposome membranes, and peroxidation was induced by UVB and AAPH. To clarify the antioxidant activity of BCE, we investigated its interactions with hydrophilic and hydrophobic regions of a membrane using fluorimetric and FTIR methods. Next, we investigated the cytotoxicity and pro-apoptotic activities of BCE in two human colon cancer cell lines (HT-29 and Caco-2) and in normal cells (IPEC-J2). In addition, the ability to inhibit enzymes that are involved in pro-inflammatory reactions was examined. Furthermore, BCE interactions with serum albumin and plasmid DNA were investigated using steady state fluorescence spectroscopy and a single molecule fluorescence technique (TCSPC-FCS). We proved that BCE effectively protects lipid membranes against the process of peroxidation and successfully inhibits the cyclooxygenase and lipoxygenase enzymes. Furthermore, it interacts with the hydrophilic and hydrophobic parts of lipid membranes as well as with albumin and plasmid DNA. It was observed that BCE is more cytotoxic against colon cancer cell lines than normal IPEC-J2 cells; it also induces apoptosis in cancer cell lines, but does not induce cell death in normal cells.

New food compositions to increase the content of phenolic compounds in extrudates

Phenolic compounds are linked to a number of health benefits, including antioxidant, antibacterial, antiglycaemic, antiviral, anticarcinogenic, anti-inflammatory and vasodilatory properties. To improve a great loss of phenolics during extrusion, researchers have investigated incorporating functional ingredients into the extrusion input mixture. Other reasons for the addition of active ingredients are the re-use of by-products from food technology, decreasing the calorie content of extruded food, inhibition of starch digestion, and the colour change of the gluten-free products. The paper presents 28 examples of new designs for extrusion based on rice, corn, cassava, sorghum, and lentil flours and on other crops, together with the analyses of phenolics. The present results show the highest total phenolic content in sorghum among cereals, and lentil flour and orange peel powder among mixtures for extrusion to prepare extrudates. The highest content of total flavonols was found in the mixture containing corn and freeze-dried red and purple potatoes.

Dietary intake of mixture coarse cereals prevents obesity by altering the gut microbiota in high-fat diet fed mice

Functional components including β-glucan, dietary fiber, resistant starch and polyphenols extracted from various coarse cereals have been reported to prevent high-fat diet (HFD) induced obesity via modulating gut microbiota. In this study, millet, maize, oat, soybean, and purple potato were ultrafine comminuted, mixed, and then extruded for the preparation of puffed mixture coarse cereals. HFD was used to investigate the effects of mixture coarse cereals on obesity and gut microbiota in mice. The results showed that dietary intake of mixture coarse cereals could decrease body weight gain and fat accumulation, improve the blood glucose tolerance and serum lipids levels, reduce the systemic inflammation, and down-regulate the expression of hepatic lipogenic genes. In addition, the levels of SCFAs and the composition of gut microbiota were investigated. The results indicated that mixture coarse cereals could promote the release of SCFAs, enhance the diversity of gut microbiota, and increase the relative abundance of Lactobacillus and Bifidobacterium, which might contribute to the anti-obesity activity. Present work suggested that the mixture coarse cereals could be developed as a nutraceutical for the prevention of HFD-induced obesity.

An alternative health crop for South Africa: Purple potato mini tuber production as affected by water and nutrient stress

Food security in South Africa ranks as one of the top ten priorities in the country. Potato is a fundamental staple food crop in South Africa, providing essential nutrition. While there are several cultivars currently in production for the potato market, there is a need to explore cultivars that are available, but not utilised within the country. Pigmented potatoes are not regarded as high value on the South African market;however,yield prospects as well as health-promoting benefits could have a positive contribution on the South African Gross Domestic Product (GDP) and on the population’s health. Potato cultivar (cv.) Salad blue(SB)seems to be a drought-tolerant crop with the ability to produce reasonable yields under severe environmental conditions. In order to promote cv. SB as a possible food security option for South Africa, there is a critical need for empirical information, describing some basic horticultural as well as biochemical information and vitamin C presence. This study investigated the potential of pigmented potato SB tubers as an alternative to high yielding white potato for the South African market.Tubers of Solanum tuberosum cv. BP1 and SB, were used for this research.The high amounts in phenolic compounds in SB can be considered to be health-promoting phytochemicals. Anticarcinogenic, antibacterial, antiviral properties have been reported. A greenhouse, bag trial with virus-free plantlets of BP1 and SB cultivars was conducted using three water and nutrient levels and favourable root zone temperature(100% without heat, 100% heated, 50% heated, 25% heated) all grown in coco peat. Cultivar SB showed nearly two-fold yield compared to the control BP1. Methanol extracts of the tubers were assessed for their total polyphenolic, flavanol, and flavonol contents as well as 1-diphenyl-2-picrylhydrazyl (DPPH) scavenging ability, ferric reducing antioxidant power (FRAP), Trolox equivalence antioxidant capacity (TEAC),anthocyanin and L-ascorbic acid assays.The aqueous extract of the SB tubers was found to contain higher level of total polyphenols (320 mg GAE/g), and flavonol (85 mg QE/g) than the extract of the BP1 tubers with values of173 mg GAE/g (total polyphenol), and67 mg QE/g (flavonol). Similarly, the methanol extract of the tuber skins also exhibited higher DPPH (818,86 IC50mg/mL), FRAP (18,19μmol AAE/g), and TEAC (911,12μmol TE/g)than the extract of the BP1with DPPH (595,99 IC50mg/mL), FRAP (10,86 μmol AAE/g) and TEAC (435,44 μmol TE/g). The present study provides useful information for farmers and health professionals in respect to increased yield and health-promoting benefits of an underutilized potato variety.

Enzymatic acylation of cyanidin-3-glucoside with fatty acid methyl esters improves stability and antioxidant activity

Cyanidin-3-glucoside is a major anthocyanin in legumes, black rice, and purple potato, and has anti-inflammatory and antioxidant properties. In the present study, the effect of acylation on cyanidin-3-glucoside lipophilicity, stability, and antioxidant capacity was investigated. Cyanidin-3-glucoside was enzymatically acylated through transesterification with fatty acid esters to produce three monoacylated cyanidin-3-glucoside esters, cyanidin-3-(6″-n-octanoyl)-glucoside, cyanidin-3-(6″-lauroyl)-glucoside, and cyanidin-3-(6″-myristoyl)-glucoside. Cyanidin-3-(6″-n-octanoyl)-glucoside had the highest thermostability and photostability of the three cyanidin-3-glucoside esters. While the in vitro antioxidant activity of cyanidin-3-(6″-n-octanoyl)-glucoside was 7.5%–14.3% lower than that of cyanidin-3-glucoside (p < 0.05), its cellular antioxidant activity increased by 33.3% (p < 0.05). Further, while cyanidin-3-(6″-lauroyl)-glucoside had lower stability and in vitro antioxidant activity than that of cyanidin-3-(6″-n-octanoyl)-glucoside, its cellular antioxidant capacity was 125.9% and 69.4% higher than cyanidin-3-glucoside and cyanidin-3-(6″-n-octanoyl)-glucoside, respectively (p < 0.05). This study demonstrated that transesterification can be used to improve the stability and in vivo antioxidant activity of cyanidin-3-glucoside.

Metal Chelates of Petunidin Derivatives Exhibit Enhanced Color and Stability.

Anthocyanins with catechol (cyanidin) or pyrogallol (delphinidin) moieties on the B-ring are known to chelate metals, resulting in bluing effects, mainly at pH ≤ 6. Metal interaction with petunidin, an O-methylated anthocyanidin, has not been well documented. In this study, we investigated metal chelation of petunidin derivatives in a wide pH range and its effects on color and stability. Purple potato and black goji extracts containing >80% acylated petunidin derivatives (25 μM) were combined with Al3+ or Fe3+ at 0 μM to 1500 μM in buffers of pH 3–10. Small metal ion concentrations triggered bathochromic shifts (up to ~80nm) at an alkaline pH, resulting in vivid blue hues (hab 200°–310°). Fe3+ caused a larger bathochromic shift than Al3+, producing green colors at pH 8-9. Generally, metal ions increased the color stability and half-life of petunidin derivatives in a dose-dependent manner, particularly at pH 8. Petunidin derivative metal chelates produced a wide range of colors with enhanced stability.

Pulp obtained after isolation of starch from red and purple potatoes (Solanum tuberosum L.) as an innovative ingredient in the production of gluten-free bread.

Starch based gluten-free bread (formulations containing mixture of corn and potato starch with hydrocolloids) are deficient in nutrients and do not contain health promoting compounds. Therefore they could be supplemented with raw materials rich in such components, especially antioxidants. Among them pseudo-cereals, seeds, fruits and vegetables are often applied to this purpose. Potato pulp produced by processing red fleshed (Magenta Love) and purple fleshed (Violetta) varieties could become a new innovative substrate for gluten-free bread enrichment, because of high levels of endogenous polyphenols, namely flavonoids, flavonols, phenolic acids and especially anthocyanins with high antioxidant potential, as well as dietary fiber. Study material consisted of gluten-free bread enriched in the pulp. Dietary fiber, acrylamide content and antioxidant and antiradical potential of the bread were determined. Sensory evaluation included crumb elasticity, porosity and other characteristics, taste and smell. Among all analyzed gluten-free breads, the sample containing 7.5% share of freeze-dried red potato pulp Magenta Love was characterized by high content of phenolic compounds and dietary fiber, pronounced antioxidant activity, low levels of potentially dangerous acrylamide and good physical and sensory characteristics. Therefore such an addition (7.5% Magenta Love) could be recommended for industrial production of gluten-free bread.

Fine structure of amylopectin and relation with physicochemical properties of three coloured potato starches

SummaryIn this study, yellow, red and purple potato starches were selected as the research objects to analyse the fine structure and the relation to the physicochemical properties. Enzymatic hydrolysis and high‐performance anion‐exchange chromatograph were employed to characterise the structure of clusters and φ, β‐limit dextrins. The average degree of polymerisation of clusters from the yellow potato starch was larger (188.57) than in red (91.31) and purple (107.32) potato starch. The molar percentage of fingerprint B chains in yellow, red and purple potato amylopectin were 58.01%, 63.60% and 60.78%, respectively, while major part of short B chains were 15.92%, 17.16% and 16.49%, respectively. The yellow potato amylopectin showed the highest density of branches values indicated that it was more tightly branched. The Pearson correlation coefficients results indicated that the fine structure of amylopectin had significant effects on the physicochemical properties of potato starches, and we can better understanding the differences of the properties among the three potato starches by studying the amylopectin fine structure.

Study on the interaction mechanism of purple potato anthocyanins with casein and whey protein

To investigate the interaction mechanism of casein (CA) and whey protein (WP) with anthocyanins from purple potato flour (PPA), multiple spectroscopic techniques and molecular docking simulation were used. After extraction and purification, two non-acylated anthocyanins and three acylated anthocyanins were identified in purple potato flour using UPLC-Q/TOF-MS. The fluorescence quenching experiment found that PPA could effectively quench the intrinsic fluorescence of CA and WP by static quenching. CA had a stronger binding affinity toward PPA than WP did, with respective Ka values of 4.23 × 105 M−1 and 1.66 × 105 M−1 at 297 K. Structural analysis indicated that PPA bound CA and WP through hydrogen bonds and van der Waals forces, and the number of bound anthocyanin molecules (n) was approximately equal to 1. The ΔG values of PPA binding with CA and WP were −30.96 kJ mol−1 and -29.16 kJ mol−1, respectively, which suggested that the binding reaction was spontaneous. Moreover, the conformational structures of CA and WP were altered by PPA binding with a decrease in α-helix and β-turn contents and an increase in β-sheet and irregular coil contents. Molecular docking analyses showed that CA and WP had different binding sites with anthocyanins. This study is helpful to better understand the interaction mechanism of CA and WP with anthocyanins and provides guidance for their applications in the food industry.

Effects of Anthocyanin Extracts from Bilberry (Vaccinium myrtillus L.) and Purple Potato (Solanum tuberosum L. var. 'Synkeä Sakari') on the Plasma Metabolomic Profile of Zucker Diabetic Fatty Rats.

This study compared the effects of the nonacylated and acylated anthocyanin-rich extracts on plasma metabolic profiles of Zucker diabetic fatty rats. The rats were fed with the nonacylated anthocyanin extract from bilberries (NAAB) or the acylated anthocyanin extract from purple potatoes (AAPP) at daily doses of 25 and 50 mg/kg body weight for 8 weeks. 1H NMR metabolomics was used to study the changes in plasma metabolites. A reduced fasting plasma glucose level was seen in all anthocyanin-fed groups, especially in the groups fed with NAAB. Both NAAB and AAPP decreased the levels of branched-chain amino acids and improved lipid profiles. AAPP increased the glutamine/glutamate ratio and decreased the levels of glycerol and metabolites involved in glycolysis, suggesting improved insulin sensitivity, gluconeogenesis, and glycolysis. AAPP decreased the hepatic TBC1D1 and G6PC messenger RNA level, suggesting regulation of gluconeogenesis and lipogenesis. This study indicated that AAPP and NAAB affected the plasma metabolic profile of diabetic rats differently.

Effects of low doses of UV-B radiation supplementation on tuber quality in purple potato (Solanum tuberosum L.)

ABSTRACT UV-B is an important environmental factor that differentially affects plant growth and secondary metabolites. However, our knowledge regarding the physiological and biochemical changes in under-ground plant organs responded to UV-B treatment remains limited. In this study, we investigated potato plant (Solanum tuberosum L.) and tuber responses to short-term supplemental UV-B exposure performed during tuber development. Our results indicated that the supplemental UV-B radiation with relative low dose had no obvious adverse impact on plant growth or tuber production. Nutritional composition analyses of tubers revealed that the contents of starch, soluble sugars, and proteins were significantly increased under lower UV-B radiation relative to controls. Similarly, low dose of UV-B treatment promoted the health-promoting compounds, including anthocyanin, phenols, and flavonoids in tubers. Moreover, higher activities of antioxidant enzymes were significantly induced in tubers in response to lower UV-B radiation. These findings suggest that short-term UV-B radiation supplementation at relative low doses can improve the tuber quality in potato plants.

Anthocyanin-Containing Purple Potatoes Ameliorate DSS-Induced Colitis in Mice

Abstract Objectives Ulcerative colitis (UC), a major form of inflammatory bowel disease (IBD), is on the rise worldwide. Approximately 3 million people suffer from IBD in the US alone, but the current therapeutic options (e.g., corticosteroids) come with adverse side effects including reduced ability to fight infections. Thus, there is a critical need for developing effective, safe and evidence-based food products with anti-inflammatory activity. This study aimed to evaluate the anti-inflammatory potential of purple-fleshed potato anthocyanins using a dextran sodium sulfate (DSS) murine model of colitis. Methods Four weeks old male C57BL/6 mice were randomly assigned to control (AIN-93 G diet), P15 (15% purple-fleshed potato) and P25 (25% purple-fleshed potato) diets for eight weeks. Colitis was induced by 2% DSS administration in drinking water for six days. Intestinal permeability was measured using FITC-dextran. Serum and colonic myeloperoxidase (MPO) levels were measured using ELISA and hexadecyltrimethylammonium bromide method, respectively. Flagellin was quantified using human embryonic kidney (HEK)-Blue-mTLR5 cells. RT-PCR was used to analyze the relative gene expression levels of cytokines and pathogenic bacteria abundance. Results 1) Purple- fleshed potato supplementation suppressed (P ≤ 0.05) the DSS-induced reduction in body weight and colon length as well as the increase in spleen and liver weight. 2) P25 alone suppressed (P ≤ 0.05) the elevation in the intestinal permeability and serum MPO levels in DSS-exposed mice. 3) The colonic mRNA expression levels of pro-inflammatory cytokines IL-6, IL-17 and TNF-α were attenuated in mice consuming P25 diet. 4) However, both purple potato diets suppressed the relative abundance of specific pathogenic bacteria such as Enterobacteriaceae and pks + E. coli. However, flagellin levels were significantly (P ≤ 0.05) lower in mice consuming the P25 diet alone. Conclusions Purple-fleshed potato diet consumption dose-dependently ameliorated the DSS-induced elevation in gut permeability, oxidative stress and inflammation and pathogenic gut bacteria. Collectively, our study results suggest that purple-fleshed potatoes have the potential to be used as a functional food in the amelioration of UC symptoms. Funding Sources USDA-NIFA awards 2016-67,017-29,285 and 2019-67,017-29,258.