Antioxidant and antiproliferative capacities of phenolics purified from Phyllanthus emblica L. fruit

Phyllanthus emblica is a widely distributed tropical medicinal plant with good therapeutic properties. Gallic acid, ellagic acid, mucic acid 1,4-lactone 3-O-gallate, isocorilagin, chebulanin, chebulagic acid and mallotusinin were isolated and purified from this plant. The antioxidant activities of these compounds were evaluated by in vitro models of scavenging superoxide anion radicals, DPPH radicals and ABTS radicals, chelating ability of ferrous ion and inhibition capability of Fe (II)-induced lipid peroxidation, respectively. The results revealed that all the tested phenolics showed strong radical scavenging activity, good potency to chelate Fe²⁺ and good inhibition ability of lipid peroxidation. Amongst mallotusinin and mucic acid 1,4-lactone 3-O-gallate were reported for the first time to have antioxidant activity. In addition, the in vitro antiproliferative activities of those phenolics against MCF-7 breast cancer cell lines were assessed. Although the growth inhibition values induced by different phenolics on MCF-7 cell line yielded different effects, all the tested phenolics had apparent capacities of inhibiting the survival of MCF-7 human cancer cell line.     

HPLC profiling of phenolics in diverse potato genotypes

Potatoes from over fifty genotypes representing cultivars, breeding lines, primitive germplasm and wild species were analysed for phenolic content and hydrophilic antioxidant capacity. Genotypes with markedly higher amounts than the most commonly consumed potatoes were identified. Chlorogenic acid was the most abundant phenolic and ranged from 22 to 473 mg/100 g dry weight. Rutin and kaempferol-3-rutinose were the most abundant flavonols. Total phenolics ranged from 1.8 to 11 mg/g DW and antioxidant capacity ranged from 27 to 219 μmol TE/g DW. Total phenolics and antioxidants in these high-phytonutrient potatoes compared favourably to 15 other analysed vegetables. With the high per capita consumption of potatoes, widespread adoption of high-phytonutrient cultivars could significantly increase dietary intake of phytonutrients.     

Structural identification of isomallotusinin and other phenolics in Phyllanthus emblica L. fruit hull

The air-dried fruit hull of Phyllanthus emblica L. was extracted with 95% ethanol, and then the extract was partitioned by diethyl ether and ethyl acetate (EA). The EA fraction was then subjected to separation and purification using silica gel and Sephadex LH-20 column chromatography repeatedly to obtain five hydrolysable tannins. They were identified as mucic acid 1,4-lactone 3-o-gallate (C1), isocorilagin (C2), chebulanin (C3), chebulagic acid (C4) and isomallotusinin (C5) using mass spectrometry and nuclear magnetic resonance (NMR) spectrometry. Isomallotusinin and chebulanin were identified from emblica dried fruit hull for the first time, and isomallotusinin was the first time identified from Phyllanthus. Furthermore, the antioxidant abilities of these hydrolysable tannins were investigated using DPPH and ABTS⁺ radical scavenging systems. All hydrolysable tannins showed strong DPPH and ABTS⁺ radical scavenging activities. Isomallotusinin and chebulagic acid exhibited the highest antioxidant activity compared to other purified compounds tested.     

Changes in physicochemical and sensory-properties of irradiated rice during storage

Milled aromatic rice (KDML-105) was γ-irradiated at doses of 0, 0.2, 0.5 and 1.0 kGy. Changes in physicochemical and sensory properties were recorded during subsequent storage in polyethylene bags at ambient temperature for 1 year. Similar trends were observed in both irradiated and non-irradiated samples. Insignificant changes in yellowness and total solids in cooking water were observed during storage of irradiated rice compared with those of naturally-aged rice. Irradiated rice showed less increase in Rapid Visco Analyzer (RVA) setback, greater reduction of RVA breakdown, and softer texture than non-irradiated rice. It also had a softer but slimy texture, off odour and inferior taste compared with the non-irradiated sample. Based on overall acceptability to panelists preferring fresh rice, non-irradiated rice could be stored for more than 1 year while rice irradiated at 0.2, 0.5 and 1.0 kGy had shelf lives of 9, 7 and 2 months, respectively.     

Characterizations of starches isolated from five different Dioscorea L. species

The physicochemical, morphological and crystal structure characterization of the starches separated from rhizomes of Dioscorea opposita Thunb. Dioscorea alata Linn., Dioscorea nipponica Makino, Dioscorea bulbifera Linn. and Dioscorea septemloba Thunb. were studied and compared. Amylose content varied between 13.58% and 20.05%. Water-binding capacity, swelling power, solubility and total starch content of starches differed significantly. Scanning electron micrographs revealed that the surface was smooth or rough, the granules were oval to spherical and the size was obviously different. D. nipponica displayed A-type pattern. D. opposita D. alata, D. septemloba and D. bulbifera starches all exhibited C-type crystal. While the crystallinity degree of the starches separated from the five species were about 33.90%, 37.63%, 43.11%, 32.06% and 53.35%, respectively. The gelatinization transition temperatures (T_o, T_p and T_c) and enthalpy of gelatinization (ΔH_gel) and peak height index (PHI) were determined. D. OT, D. AL and D. BL starches showed the higher enthalpy of gelatinization. Pasting viscosity of D. OT and D. BL starches were much higher than others. The five plants could be separated into two groups: D. OT, D. AL and D. BL; D. ST and D. NM.     

Vapour treatments with methyl salicylate or methyl jasmonate alleviated chilling injury and enhanced antioxidant potential during postharvest storage of pomegranates

Pomegranates were treated after harvest with methyl jasmonate (MeJa) or methyl salicylate (MeSa) at two concentrations (0.01 and 0.1 mM), and then stored under chilling temperature for 84 days. Control fruits exhibited chilling injury (CI) symptoms manifested by pitting and browning, the severity being enhanced as storage time advanced, and accompanied by softening and electrolyte leakage (EL). The CI symptoms were significantly reduced by MeJa or MeSa treatments, without significant differences among treatments or applied dose. In addition, both treatments significantly increased total phenolics and anthocyanins with respect to controls. Hydrophilic (H-TAA) and lipophilic (L-TAA) total antioxidant activity decreased in control arils, but in both MeJa and MeSa treated fruits H-TAA increased while no significant changes occurred for L-TAA. Results would suggest that both MeJa and MeSa have potential postharvest applications in reducing CI, maintaining quality and improving the health benefits of pomegranate fruit consumption by increasing the antioxidant capacity.     

The effects of high hydrostatic pressure at subzero temperature on the quality of ready-to-eat cured beef carpaccio

We compared the application of high hydrostatic pressure (HHP) on unfrozen carpaccio (HHP at 20°C) and on previously-frozen carpaccio (HHP at -30°C). HHP at 20°C changed the color. The pressure increase from 400 to 650MPa and the time increment from 1 to 5min at 400MPa increased L* and b*. a* decreased only with 650MPa for 5min at 20°C. The prior freezing of the carpaccio and the HHP at -30°C minimized the effect of the HHP on the color and did not change the shear force, but increased expressible moisture as compared to the untreated carpaccio. HHP at 20°C was more effective in reducing the counts of microorganisms (aerobic total count at 30°C, Enterobacteriaceae, psychrotrophs viable at 6.5°C and lactic acid bacteria) than HHP at -30o C. With HHP at 20°C, we observed a significant effect of pressure and time on the reduction of the counts.     

Identification of phenolics in the fruit of emblica (Phyllanthus emblica L.) and their antioxidant activities

An activity-directed fractionation and purification process was used to identify the antioxidative components of emblica fruit. Dried fruit of emblica was extracted with methanol and then partitioned by ethyl ether, ethyl acetate, butanol and water. The ethyl acetate fraction showed the strongest 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity among four fractions. The ethyl acetate fraction was then subjected to separation and purification using Sephadex LH-20 chromatography and reverse-phase high-performance liquid chromatography (HPLC). Six compounds were identified to be geraniin (1), quercetin 3-β-d-glucopyranoside (2), kaempferol 3-β-d-glucopyranoside (3), isocorilagin (4), quercetin (5), and kaempferol (6), respectively, by spectral methods, ¹H and ¹³C nuclear magnetic resonance (NMR) spectroscopy, ultraviolet–visible (UV–Vis) spectrophotometry and mass spectroscopy (MS), and comparison with literatures. Compounds 2–4 and 6 were identified from emblica fruit for the first time. Furthermore, the antioxidant activities of purified compounds were screened for their antioxidative potential using lipid peroxidation and DPPH systems. All the purified compounds showed strong antioxidant and radical scavenging activities. Amongst, geraniin showed the highest antioxidant activity (4.7 and 65.7 μM of IC₅₀ values for DPPH and lipid peroxidation assay, respectively) than other purified compounds.     

Yeast biocontrol of fungal spoilage of pears stored at low temperature

To reduce the use of fungicides, biological control with yeasts has been proposed in postharvest pears. Most studies of antagonists selection have been carried out at room temperature. However, in regions like North Patagonia where fruits are stored at − 1/0 °C during 5-7 months the selection of potential antagonist agents must be carried out at low temperature. In this study, 75 yeast cultures were isolated from healthy pears from two Patagonian cold-storage packinghouses. Aureobasidium pullulans, Cryptococcus albidus, Cryptococcus difluens, Pichia membranifaciens, Pichia philogaea, Rhodotorula mucilaginosa and Saccharomyces cerevisiae yeast species were identified. Additionally, 13 indigenous isolates of Penicillium expansum and 10 isolates of Botrytis cinerea were obtained from diseased pears, characterized by aggressiveness and tested for sensitivity to postharvest fungicides. The yeasts were pre-selected for their ability to grow at low temperature. In a first biocontrol assay using the most aggressive and the most sensitive isolate of each pathogen, two epiphytic isolates of A. pullulans and R. mucilaginosa were the most promising isolates to be used as biocontrol agents. They reduced the decay incidence by P. expansum to 33% and the lesion diameter in 88% after 60 days of incubation in cold. Foreign commercial yeast used as a reference in assays, only reduced 30% of lesion diameter in the same conditions. Yeasts were not able to reduce the incidence of B. cinerea decay. The control activity of the best two yeasts was compared with the control caused by the fungicides in a second bioassay, obtaining higher levels of protection against P. expansum by the yeasts. These two regional yeasts isolates could be promising tools for the future development of commercial products for biological control.     

Effects of maturity stage and storage on cactus berry (Myrtillocactus geometrizans) phenolics,vitamin C,betalains and their antioxidant properties

The CIE-LAB coordinates, total phenols, betalains and vitamin C were determined in berry cactus fruit at different maturity stages, before and after storage. The contribution of those antioxidant compounds to the Trolox equivalent antioxidant capacity (TEAC) and oxygen radical absorbance capacity (ORAC) were assessed as well. The simple phenolics profile was determined by high performance liquid chromatography with diode array detection (HPLC-DAD). After storage, the fruit develops similar colour compared to ripe and overripe fresh fruit. Total phenols and vitamin C were reduced by up to 82.4% and 68.5%, respectively, as fruit matures and after storage. On the contrary, beta-cyanins increase up to 51.8% as fruit matures and after storage. Betalains contribute with 58.4% to TEAC and up to 43.4 to ORAC values. Gallic acid and quercetin were the major simple phenolics present. Due to the contents of antioxidant compounds and the outstanding antioxidant activities, cactus berries could contribute to health.     

Physicochemical, crystallinity, pasting and morphological properties of bean starch oxidised by different concentrations of sodium hypochlorite

The effect of bean starch oxidation at different active chlorine concentrations (0.5%, 1.0% and 1.5%) on the physicochemical, crystallinity, pasting and morphological properties of starch was investigated. The carbonyl content, carboxyl content, starch colour, swelling power, solubility, gel hardness, X-ray crystallinity, pasting properties, gelatinisation characteristics and morphology of the starches were evaluated. The bean starch oxidised with 0.5% active chlorine had the characteristic of a slightly crosslinked starch. As compared to the native and 0.5% active chlorine-oxidised starches, active chlorine at 1.0% and 1.5% increased the carbonyl content, carboxyl content and solubility of the starches. Moreover, these concentrations of active chlorine decreased the swelling power, gel hardness, relative crystallinity, breakdown, peak viscosity and setback, as compared to the native and 0.5% active chlorine-oxidised starches. The starch granules oxidised with 1.5% active chlorine had imperfections in their structure, and its surface appears to be rougher than the other granules.     

Variation of total phenolics, anthocyanins, ellagic acid and radical scavenging capacity in various raspberry (Rubus spp.) cultivars

The aim of this study was to assess the level of some phytochemicals in 19 raspberry cultivars grown in Lithuania. The content of total ellagic acid measured after 20 h acidic hydrolysis of investigated raspberry cultivars, varied from 119.8 (cv. ‘Pokusa’) to 323.5 mg/100 g (cv. ‘Bristol’). The content of total phenolics ranged from 278.6 (cv. ‘Pokusa’) to 714.7 mg/100 g (cv. ‘Bristol’). The total anthocyanins content varied from 2.1 (yellow cv. ‘Beglianka’) to 325.5 mg/100 g (black cv. ‘Bristol’). The radical scavenging capacity of the tested raspberry cultivars highly correlating with their total phenolics and total ellagic acid content (r = 0.90 and 0.92, respectively). The results of this study expand the knowledge about variation in the content of valuable bioactive compounds in raspberries and may help for the selection and validation of the most productive cultivars.     

Immunomodulatory and anticancer activities of phenolics from emblica fruit (Phyllanthus emblica L.)

There is a paucity of studies on the immunomodulatory properties of fruit extracts of emblica with the emphasis on lymphocytes. Therefore, the aim of the study was to evaluate the immunomodulatory properties and anticancer potential of six phenolic compounds from emblica fruit by in vitro proliferation assay. Effects of these compounds on splenocyte proliferation and the cytotoxicity to both human breast cancer cell (MCF-7) and human embryonic lung fibroblast cell (HELF) were determined by the MTT method. Significantly stimulatory effects (P < 0.05) were found for geraniin and isocorilagin. The concentration of geraniin, quercetin 3-β-d-glucopyranoside, kaempferol 3-β-d-glucopyranoside, isocorilagin, quercetin, kaempferol and rutin to obtain 50% of stimulatory effect was 56, 123, 242, 42, 73, 93 and 92 μg/ml, respectively. The assay of anticancer activities suggested that geraniin and isocorilagin exhibited higher cytotoxicities than other compounds against MCF-7 with IC₅₀ of 13.2 and 80.9 μg/ml, respectively. Isocorilagin exhibited a strong cytotoxicity to HELF cell with IC₅₀ of 51.4 μg/ml. Geraniin, quercetin, kaempferol and their glycosides had weak cytotoxicity against HELF cells. Paclitaxel showed a strong cytotoxicity to MCF-7 and HELF with IC₅₀ of 6.8 and 14.5 μg/ml, respectively. These findings are in line with the reported potent antioxidant activity. These results suggested that the antitumour activity of these compounds might be achieved by immunomodulatory properties which could partially be attributed to their antioxidant activity.     

Changes in physicochemical properties and bactericidal efficiency of acidic electrolyzed water ice and available chlorine decay kinetics during storage

Acidic electrolyzed water ice (AEW ice) is a new kind of bactericide used in preservation or cold sterilization of food products. The aim of this study was to investigate changes in the physicochemical properties (oxidation reduction potential (ORP), pH value and available chlorine concentration (ACC)), bactericidal efficiency, and decay kinetics of available chlorine in AEW ice during 10 h of storage time. Results indicated that pH changes of AEW ice did not have a significant difference (p > 0.05) during the first 6-h storage, after 6 h, the pH of AEW ice prepared with ≤1 g/l NaCl solution changed more slowly than that of AEW ice prepared with >1 g/l NaCl solution. Both ORP and ACC decreased with storage time. The ACC of AEW ices prepared from >1.5 g/l NaCl solutions decreased faster and in a greater extent than those prepared from ≤1.5 g/l NaCl solutions. According to the correlation analysis, the correlation coefficients between pH, ORP, and ACC and Vibrio parahaemolyticus inactivation were −0.831, 0.787 and 0.944, respectively, and those between the above parameters and Listeria monocytogenes inactivation were −0.814, 0.701 and 0.97, respectively. Based on the kinetic study, the decay of ACC fitted the first order kinetics.     

Influences of preharvest spraying Cryptococcus laurentii combined with postharvest chitosan coating on postharvest diseases and quality of table grapes in storage

The effects of preharvest spray with Cryptococcus laurentii combined with chitosan coating after harvest on decay and quality of table grapes during storage periods were evaluated in the present study. Preharvest spray with C. laurentii (PreA) significantly decreased decay index (DI), and postharvest chitosan coating (PCC) enhanced the effectiveness of the pre-harvest spray when fruits were stored at 0 °C. PreA combination with PCC increased the activities of polyphenol oxidase (PPO) and phenylalanine ammonia-lyase (PAL) of fruit in storage. PreA + PCC treatment was effective in reducing weight loss of fruits by 85% at 17 d storage and 38% at 42 d storage as compared to PreA alone at the same stage. In addition, PreA enhanced the ratio of soluble solids content (SSC) to titratable acid (TA) by 12% at harvest time, 7% at 17 d storage and 25% at 42 d storage, mainly by increasing SSC and decreasing TA in fruit stored at 0 °C. These results suggested that integration of preharvest spray with C. laurentii and postharvest chitosan coating treatment may be a promising management strategy for decay control and quality maintenance of table grapes.     

The effect of high hydrostatic pressure on the microbiological quality and safety of carrot juice during refrigerated storage

The microbial quality of untreated and pressure-treated carrot juice was compared during storage at 4, 8 and 12 °C. High pressure treatment at 500 MPa and 600 MPa (1 min/20 °C) reduced the total counts by approximately 4 log CFU ml⁻¹ and there was very little growth of the survivors during storage at 4 °C for up to 22 days. Total counts increased during storage of pressure-treated juice at 8 °C and 12 °C but took significantly longer to reach maximum levels compared to the untreated juice. The microflora in the untreated juice consisted predominantly of Gram-negative bacteria, identified as mostly Pantoea spp., Erwinia spp. and Pseudomonas spp. Initially the pressure-treated juice contained low numbers of spore-forming bacteria (Bacillus spp. and Paenibacillus spp.) and Gram-positive cocci; the spore-formers continued to dominate during storage.     

Antioxidant activity and phenolic content of 16 raisin grape (Vitis vinifera L.) cultivars and selections

Six raisin grape cultivars and 10 new raisin grape selections were analyzed for antioxidant activity (ABTS assay) and for total and individual phenolic compounds. Samples were freeze–dried and values are reported on a dry weight basis. Antioxidant activity across the 16 samples ranged from 7.7 to 60.9 μmol Trolox/g DW, with A95-27 exhibiting the greatest activity. Total phenolic content, determined in gallic acid equivalents using the Folin–Ciocalteau assay, ranged from 316.3 to 1141.3 mg gallic acid/100 g DW and was strongly correlated (r = 0.990) with antioxidant results. Concentrations of individual phenolics were determined by HPLC. trans-Caftaric acid was the predominant compound in all samples. A95-15 contained the lowest concentration (153.5 μg/g DW) of caftaric acid, while Fiesta contained the highest concentration (598.7 μg/g DW). Selections A56-66, A95-15, and A95-27 had much higher levels of catechin (86.5–209.1 μg/g DW) and epicatechin (126.5–365.7 μg/g DW) than the other samples.     

Effect of high pressure, temperature, and storage on the color of porcine longissimus dorsi

The color of pork longissimus dorsi high pressure (HP) treated at 200 to 800MPa at 5 and 20°C for 10min was determined to a high degree by pressure level and to a lesser degree by temperature. Severe color changes appeared up to a threshold pressure at 400MPa. HP treatment at 20°C compared to 5°C resulted in meat, which was less red and slightly lighter. Storage at 2°C for 6days had no effect on lightness due to no further protein denaturation, but meat HP treated above 300MPa became significantly less red and more yellow within the first day of storage. Reflectance spectra showed that a short-lived ferrohemochrome myoglobin species was formed during HP treatment at 300 to 800, but transformed into a brown, ferric form of the pigment within the first day of storage. This explains the observed changes in the redness and yellowness after one day of storage.     

Nutritional characterization and changes in quality of Salicornia bigelovii Torr. during storage

Salicornia bigelovii Torr. (sea-beans or drift seeds in English, sea-asparagus in Chinese) is an oil-seed plant tolerant to seawater irrigation and perishable with a shelf life of only about 6 days at ambient temperature (25 °C). To provide a potential food supplement, nutritional value of S. bigelovii were determined together with its postharvest quality as affected by storage temperatures (0 °C, 2 °C, 8 °C and 25 °C). Nutritional analyses showed that S. bigelovii contained high vitamins and minerals, which made it an ideal nutritional and diet supplement. Storing S. bigelovii at low temperatures could be a practical technique to extend storage life by reducing the quality degradation. After conducing sensory evaluations and determining ascorbic acid and chlorophyll contents, the optimal temperature for storing S. bigelovii was around 2 °C. This research will help to develop technically effective and energy efficient methods for prolonging the shelf life of S. bigelovii.     

Total phenolics,ascorbic acid,and antioxidant capacity of noni (Morinda citrifolia L.) juice and powder as affected by illumination during storage

Total phenolics, ascorbic acid, and antioxidant capacity of noni (Morinda citrifolia L.) juice and powder were determined during storage at 24 °C. After 2 weeks of storage, illuminated noni juice lost 32% of total phenolics, 89% of ascorbic acid, and 46–65% of antioxidant capacity—about 8%, 22%, and 9–15% more than unilluminated juice. Both illuminated and unilluminated juice lost 97% of ascorbic acid by 4 weeks. The difference in antioxidant characteristics between illuminated and unilluminated juice became insignificant at 12 weeks. After 12 weeks, illuminated noni powder lost 21% of total phenolics, 17% of ascorbic acid, and 23–36% of antioxidant capacity—about 13%, 4%, and 7–19% more than the unilluminated powder. Noni powder in brown bottles retained antioxidant characteristics significantly greater than that in clear bottles. Protection from light effectively reduced degradation of antioxidant characteristics of noni juice for only 2 weeks but those of noni powder for at least 3 months.