Inhibitory effect of raspberries on starch digestive enzyme and their antioxidant properties and phenolic composition

Seven primocane fall-bearing raspberry (Rubus idaeus L.) cultivars, Nova (red), Dinkum (red), Heritage (red), Autumn Britten (red), Josephine, Anne (yellow), Fall Gold (yellow) were analysed for potential health promoting properties including their inhibitory effect on starch and fat digestive enzymes, antioxidant activities, and phenolic composition. The tested raspberry extracts showed no detectable inhibition of pancreatic α-amylase and lipase. However, all the extracts exhibited potent inhibition of α-glucosidase with IC₅₀ from 16.8 to 34.2 μg/mL. Four phenolic compounds, ellagic acid, cyanidin-diglucoside, pelargonidin-3-rutinoside, and catechin were identified as the active α-glucosidase inhibitors. The raspberry extracts also possessed significant antioxidant activities with oxygen radical absorbance capacities (ORAC) ranging from 136.7 to 205.2 μmol Trolox equivalents (TE)/g dry weight fruit and DPPH radical scavenging activities from 305 to 351 μmol TE/g. The total phenolic content of raspberry cultivars varied significantly from 40.9 to 98.5 mg of gallic acid equivalents/g dry weight. The anthocyanin content varied widely from 0.1 to 9.5 mg cyanidin 3-glucoside equivalents/g. Nine phenolic acids were quantified in raspberries and their total amounts varied from 157.3 to 713.5 μg/g. The enzyme inhibition and antioxidant properties of raspberry cultivars were not correlated with their total phenolic, anthocyanin, and phenolic acid content. Overall, ‘Dinkum’ and ‘Josephine’ raspberry varieties possess higher total phenolic content, ORAC, DPPH radical scavenging activity, and α-glucosidase inhibitory activity than other five cultivars.     

Phenolics, betacyanins and antioxidant activity in Opuntia joconostle fruits

Sour prickly pears (xoconostles) are fruits from Opuntia joconostle cactus, which are cultivated in the central Mexico area. Phenolic and pigment content in various parts of O. joconostle fruits were analyzed. The antioxidant activity of a methanolic extraction and different semi-purified fractions were also evaluated by the DPPH⁺ method. Xoconostle fruits were obtained from a commercial orchard in Mexico State. Fruits were analyzed as whole fruit and each fruit part including pericarp, mesocarp and endocarp. Samples were homogenized and kept at 4 °C until sample preparation. Total phenolic content and total flavonoid content varied among the different parts of the fruit. The highest amount of phenolic compounds and total flavonoids content were found in pericarp 2.07 mg gallic acid equivalents (GAE)/g fresh weight (FW) and 0.46 mg(+)-catechin equivalents (CE)/g FW respectively. Seven phenolics were identified as protocatechuic, 4-hydroxybenzoic, caffeic, vanillic and syringic acids, rutin, and quercetin. The color of the fruit parts was mainly due to the presence of betacyanins. The betacyanin concentration was higher in the endocarp (23.03 mg betanin equivalents/100 g fresh weight) than in the pericarp and mesocarp. Betacyanins were identified by HPLC-PDA-MS as betanin, isobetanin, betanidin, isobetanidin, and phyllocactin. Methanolic extracts and semi-purified fractions A (phenolics and flavonols) and B (betacyanins) of xoconostle showed high antioxidant activity mainly in the pericarp. These results suggest that xoconostle is a rich source of antioxidant compounds such as phenolic compounds and betacyanins.     

Effect of defatted almond flour on cooking,chemical and sensorial properties of gluten‐free fresh pasta

The aim of this work was to analyse the influence of defatted almond flour on soya bean‐based gluten‐free pasta. Optimal cooking time of pasta varied between 2.0 and 3.5 min, while cooking loss ranged 6.1% and 19.7%. The total protein content of samples varied from 30.4% to 41.0% (dry basis, db) in cooked pasta. The total phenols content of cooked samples varied between 1.66 and 2.99 mg ellagic acid equivalent/g, while the antioxidant activity (DPPH?) ranged between 19.1% and 41.9%. The sensory test showed no significant differences between the formulated pasta samples among brightness (3.20–3.27), surface appearance (1.14–1.20), hardness (2.14–2.36) and elasticity (1.56–1.71). Pasta developed is an innovative product that improves nutritional and functional properties of gluten‐free pasta compared to gluten‐free and traditional wheat flour pasta available on market.     

Sugars,organic acids,phenolic composition and antioxidant activity of sweet cherry (Prunus avium L.)

Sugars, organic acids, phenolics and anthocyanins in fruits of 13 sweet cherry cultivars: Badascony, Burlat, Early Van Compact, Fercer, Fernier, Ferprime, Lala Star, Lapins, Noire de Meched, Sylvia, Vesseaux, Vigred (red-coloured) and Ferrador (bi-coloured) were quantified by HPLC. Sweet cherry cultivars of different pomological characteristics and different time of ripening were evaluated sensorily. Cultivars were evaluated for their total phenolic content and antioxidant activity. The sum of sugars (glucose, fructose, sucrose and sorbitol) ranged from 125 to 265 g/kg fresh weight (FW) and the sum of organic acids (malic, citric, shikimic and fumaric) ranged from 3.67 to 8.66 g/kg FW. Total phenolic content ranged from 44.3 to 87.9 mg gallic acid equivalents/100 g FW and antioxidant activity ranged from 8.0 to 17.2 mg ascorbic acid equivalent antioxidant capacity mg/100 g FW. The correlation of antioxidant activity with total phenolics content and content of anthocyanins was cultivar dependent.     

Fatty acid composition,oxidative stability,antioxidant and antiproliferative properties of selected cold-pressed grape seed oils and flours

Cold-pressed chardonnay, muscadine, ruby red, and concord grape seed oils and their defatted flours were studied for their fatty acid composition, oxidative stability and antioxidant and antiproliferative activities. The phenolic profiles of the seed flours were also measured. The most abundant fatty acid in the oils was linoleic acid, ranging from 66.0 g/100 g of total fatty acids in ruby red seed oil to 75.3 g/100 g of total fatty acids in concord seed oil. The oils were also high in oleic acid and low in saturated fat. Ruby red grape seed oil recorded the highest oxidative stability index of 40 h under the accelerated conditions. Total phenolic content (TPC) was up to 100 times lower in the oils than in the flours. Lutein, zeaxanthin, cryptoxanthin, β-carotene, and α-tocopherol levels were also measured. DPPH radical-scavenging capacity ranged from 0.07 to 2.22 mmol trolox equivalents (TE)/g of oil and 11.8 to 15.0 mmol TE/g of flour. Oxidative stability of menhaden fish oil containing extracts of the seed flours was extended by up to 137%. HPLC analysis was conducted to determine the levels of free soluble, soluble conjugated and insoluble bound phenolics in the seed flours. The phenolic compounds analyzed included catechin, epicatechin, epicatechin gallate, quercetin, gallic acid, and procyanidins B1 and B2. Antiproliferative activity was tested against HT-29 colon cancer cells. All of the seed flours and muscadine seed oil registered significant (P < 0.05) inhibition of cancer cell growth. The results from this study demonstrate the potential of developing value-added uses for these seed oils and flours as dietary sources of natural antioxidants and antiproliferative agents for optimal health.     

Enhancement of pasta antioxidant activity with oregano and carrot leaf

Five different pasta formulations were prepared using different concentrations of carrot leaf meal (CLM) and oregano leaf meal (OLM). One control formulation (wheat flour and semolina, 70:30 w/w) and four other formulations were prepared using the following amounts of leaf meals: 5% CLM and 5% OLM (I), 10% CLM (II), 10% OLM (III), and 10% CLM, 10% OLM (IV). The highest content of alpha-linolenic acid was found in formulations II and IV, which also had a reduced n-6/n-3 ratio, 3.6 (IV), when compared to the control, which was 19.8. All the samples enhanced with leaf meals showed antioxidant activity by the DPPH radical method; however, it was higher in formulation IV, which was the same observed for phenolic compounds. Pasta added with leaf meals lost more solubles, had shorter cooking time and a lower weight increase than the control pasta. All formulations had significant sensory acceptance.     

Preliminary characterisation of cornelian cherry (Cornusmas L.) genotypes for their physico-chemical properties

Fruit weight, antioxidant capacity, total anthocyanins, total phenolics, ascorbic acid, soluble solid content (SSC), reducing sugar and acidity of a number of selected cornelian cherry (Cornusmas L.) genotypes of varied pigmentation were investigated. Two methods, namely β-carotene bleaching and ferric reducing antioxidant power (FRAP) were used to determine total antioxidant capacity, while Folin–Ciocalteu reagent was used to determine total phenols. Fruit weight, SSC and ascorbic acid content of genotypes were 2.09–9.17; 12.53–21.17% and 29–112 mg/100 g, respectively. Antioxidant activity and total phenolic content varied among genotypes and 44-18 genotype had the highest antioxidant capacity using both methods. This genotype also had the highest total phenolic (74.8 mg GAE/g DW) and total anthocyanin (115 mg cyanidin-3-glucoside equivalents /100 g FW) content. There are linear relationships between antioxidant capacities and total phenols. The present study demonstrates the potential of certain cornelian cherry genotypes, notably 44-18, for improvement of nutritional value through germplasm enhancement programmes.     

Organic acids,antioxidant capacity,phenolic content and lipid characterisation of Georgia-grown underutilized fruit crops

Four underutilized Georgia-grown fruit crops, namely loquat (Eriobotrya japonica), mayhaw (Crataegus sp.), fig (Ficus carica), and pawpaw (Asimina triloba), and their leaves were analysed for total polyphenols by Folin–Ciocalteau method, and antioxidant capacity by ferric-reducing antioxidant power (FRAP) and Trolox-equivalent antioxidant capacity (TEAC) assays. Organic acids and phenolic compounds were identified by RP-HPLC. For lipid profile, fruits were separated into two fractions – seed and fruit (i.e., without seed); lipid was extracted using the Folch method and analysed for fatty acids, phytosterols, tocopherols, and phospholipids. The major organic acid identified in all samples was malic acid (177–1918 mg/100 g FW). The predominant phenolic acids in all the fruits were gallic (1.5–6.4 mg/100 g FW) and ellagic (0.2–33.8 mg/100 g FW), and the most abundant flavonoid was catechin (12.2–37.8 mg/100 g FW). Total lipid content varied from 0.1% in mayhaw fruit to 21.5% in pawpaw seed. Linoleic acid was the predominant fatty acid in all of the samples (28.2–55.7%).     

Quality of spaghetti pasta containing Mexican common bean flour (Phaseolus vulgaris L.)

The objective of this research was to study the effect of the addition of common bean flour to semolina on the cooking quality and total phenolic content of pasta. Pasta was obtained at three temperatures (60, 70 and 80 °C) and two levels of added common bean flour (15% and 30%); plain pasta (100% semolina) was used as control. Moisture, optimal cooking time, cooking loss, water absorption capacity, colour change, firmness and total phenolic and furosine contents were measured. The cooking time and water absorption were diminished in spaghetti pasta with added common bean flour; cooking loss increased and firmness decreased as a function of the bean flour percentage. A linear relationship between colour change and common bean flour content in pasta was found. Increases of furosine and phenolic contents in pasta with the addition of bean flour were observed.     

Effect of insoluble dietary fibre addition on technological,sensory, and structural properties of durum wheat spaghetti

Insoluble fibres are important in human health and disease prevention and can be incorporated into food. High fibre pasta prepared with bran is typically inferior quality compared to durum pasta. This study compared spaghetti prepared from durum semolina substituted with various amounts of either durum bran or germ (pollard) dried at high temperature. Pasta was evaluated for cooking properties, texture, sensory, fibre content, antioxidant status (AO) and in vitro starch digestibility to determine the dose producing acceptable quality. Pollard at 10% substitution had minimal impact on quality with higher AO and fibre. Above 30%, pasta had undesirable colour, sensory properties and higher starch digestion. Although bran substituted pasta had undesirable sensory and technological properties, especially at 30% incorporation, it does provide more dietary fibre and antioxidants than regular pasta and does not affect starch digestibility. Interestingly, a significant amount of AO was retained in the cooked pasta. The study illustrates the value of structural analysis to explain observed technological properties of the product with fibre inclusion.     

Phytochemical constituents and antioxidant capacity of different pecan [Carya illinoinensis (Wangenh.) K. Koch] cultivars

Six pecan cultivars were analyzed for their antioxidant capacity (AC), total phenolics (TP), condensed tannin (CT), HPLC phenolic profile, tocopherol and fatty acid composition. Kernels which included the outer brown testa or pellicle, and shells which is the hard cover that surrounds the kernel, were evaluated for each cultivar. Strong correlations were found in kernels between AC and TP for both DPPH (r² = 0.98) and AC_ORAC (r² = 0.75) antioxidant assays. AC_ORAC values ranged from 372 to 817 μmol trolox equivalents/g defatted kernel, corresponding to Desirable and Kanza cultivars, respectively. CT ranged from 23 to 47 mg catechin equivalents/g defatted kernel and TP from 62 to 106 mg of chlorogenic acid equivalents/g defatted kernel. After a consecutive basic-acid hydrolysis, gallic acid, ellagic acid, catechin and epicatechin were identified by HPLC. The TP, AC and CT were 6, 4.5 and 18 times higher, respectively, for shells compared to kernels. The presence of phenolic compounds with high antioxidant capacity in kernels and shells indicates pecans can be considered an important dietary source of antioxidants.     

Chemical composition, cooking quality, and consumer acceptance of pasta made with dried amaranth leaves flour

Pasta is a staple food in many countries. Amaranth is a pseudo-cereal being re-discovered because of its nutritional properties. The main objective of this study was to evaluate the potential of the green material of the amaranth plant (leaves) as a component for pasta production and its effect on the pasta quality and consumer acceptance. Dried amaranth (Amaranthus caudatus) leaves and spinach leaves flours were prepared. Pasta samples were manufactured following a small-scale pilot procedure. Amaranth pasta samples were evaluated for its chemical composition, cooking quality, textural, and sensory/consumer acceptance. Results showed that pasta made with dried amaranth leaves had similar chemical composition (protein content: 14.18 g/100 g, Fe content: 9.1 mg/100 g), cooking quality (2.15 pasta weight increase, 4.47% residue loss), textural characteristics (firmness and adhesiveness), and sensory acceptance than green pasta made with dried spinach leaves. Since amaranth leaves have similar nutritional characteristics to spinach leaves and since this biomass in not currently used for food purposes, this study points out that amaranth leaves could be technically used for pasta production and that consumer acceptance of pasta made with amaranth green leaves flour is similar to that of pasta made with spinach.     

Fruit quality and bioactive compounds relevant to human health of sweet cherry (Prunus avium L.) cultivars grown in Italy

The fruit quality characteristics, phenolic compounds and antioxidant capacities of 24 sweet cherry (Prunus avium L.) cultivars grown on the mountainsides of the Etna volcano (Sicily, Italy) were evaluated. High-performance liquid chromatographic methods were used to identify and quantify sugars, organic acids and phenolics. A total of seven phenolic compounds were characterised as hydroxycinnamic acid derivatives (neochlorogenic acid, p-coumaroylquinic acid and chlorogenic acid) and anthocyanins (cyanidin 3-glucoside, cyanidin 3-rutinoside, pelargonidin 3-rutinoside and peonidin 3-rutinoside). The total anthocyanin content ranged from 6.21 to 94.20 mg cyanidin 3-glucoside equivalents/100 g fresh weight (FW), while the total phenol content ranged from 84.96 to 162.21 mg gallic acid equivalents/100 g FW. The oxygen radical absorbance capacity (ORAC) assay indicated that fruit of all genotypes possessed considerable antioxidant activity. The high level of phenolic compounds and antioxidant capacity of some sweet cherry fruits implied that they might be sources of bioactive compounds that are relevant to human health.     

Cytoprotective and antioxidant activity of free,conjugated and insoluble-bound phenolic acids from swallow root (Decalepis hamiltonii)

Swallow root (Decalepis hamiltonii) was extracted for free (SRFP), conjugated (SRCP) and insoluble-bound phenolic acids (SRIBP), and evaluated for cytoprotectivity, 1,1,diphenyl-2-picrylhydrazyl (DPPH) scavenging ability, reducing power and protection to DNA damage. In addition, the constituent phenolic acids in the extracts were also analysed. Results indicated a total phenol content of 20.72, 7.97 and 11.52 mg gallic acid equivalents (GAE)/g for SRFP, SRCP and SRIBP extracts, respectively. At 0.12 μg/mL concentration SRCP showed 87% cytoprotection (on NIH 3T3 cells) compared to SRFP (47%) and SRIBP (65%). DPPH radical scavenging activity indicated an IC₅₀ of 0.046, 0.06 and 0.128 μg/mL for SRCP, SRIBP and SRFP, respectively. Also, SRCP showed higher reducing power and DNA protectivity (80%). HPLC analysis of phenolic acid extracts showed the presence of hydroxybenzoate and cinnamate derivatives. Among the phenolics identified gallic, gentisic, protocatechuic and p-coumaric acids were the major contributors to antioxidant activity.     

Chemical composition,anthocyanins, non-anthocyanin phenolics and antioxidant activity of wild bilberry (Vaccinium meridionale Swartz) from Colombia

Berries of Vaccinium meridionale Swartz native to Colombia were analysed for chemical composition, total phenolic content, anthocyanin content, and antioxidant activity. In addition, high-performance liquid chromatography with photodiode array detection (HPLC–DAD) and HPLC-electrospray ionisation tandem mass spectrometry (ESI–MS/MS) were used to determine anthocyanin and phenolic composition. Anthocyanin content was 329.0 ± 28.0 mg cyanidin 3-glucoside equivalents/100 g (fresh weight) FW and total phenolic content was 758.6 ± 62.3 mg gallic acid equivalent/100 g FW. Cyanidin 3-galactoside was the major anthocyanin while the most abundant non-anthocyanin phenolic was chlorogenic acid.     

Comparative antioxidant activity of extracts from leaves,bark and catkins of Salix aegyptiaca sp.

Leaves, bark and catkins of Salix aegyptiaca L. were extracted into solvents of increasing polarity from cyclohexane (non-polar), butanol, ethanol and water (polar) and analysed for their antioxidant capacity, total phenol and flavonoids. The highest antioxidant activity (19 μg/ml IC₅₀ for inhibition of DPPH radical activity), total phenolic content (212 mg gallic acid equivalents/g of dried extract) and total flavonoid (479 mg catechin equivalents/g of dried extract) was observed in the ethanolic extract of bark. HPLC identification of phenolic compounds from the extracts indicated the presence of gallic acid, caffeic acid, vanillin and p-coumaric acid, myricetin, catechin, epigallocatechin gallate, rutin, quercetin as well as salicin. Our data indicates the presence of high amounts of phenols and flavonoids in different parts of S. aegyptiaca species and propose that extracts from this plant may be utilised as a source of health promoting antioxidants.     

Influence of winemaking techniques on the resveratrol content, total phenolic content and antioxidant potential of red wines

In this paper, the influence of winemaking techniques and cultivars on the resveratrol content, total phenolic content and antioxidant potential of red wines was studied. Wines were made from the cultivars Merlot, Cabernet Sauvignon, Pinot Noir and Prokupac. Applied winemaking technologies included thermovinification and separation of must from pomace. The analysis of trans- and cis-resveratrol in wines was performed by HPLC, while the total phenolic content and antioxidant potential was determined by spectrophotometric methods. The total resveratrol content in analysed samples ranged from 0.35 to 4.85 mg/l; Merlot wines had the highest average resveratrol content, while the lowest was found for native cultivar Prokupac. Although the resveratrol content depended on grape variety, correlation between the winemaking technology applied and the resveratrol level in wines was not observed. The total phenolic content (TPC) varied from 544.4 to 1410.4 mg/l expressed as gallic acid equivalents, and the antioxidant potential, assayed by DPPH in terms of SC₅₀ (mean scavenging concentration), ranged from 0.58 to 2.91 μl/ml. Obtained results showed that thermovinificated wine samples had higher amount of phenolic compounds. Significant negative correlation was observed (p < 0.05) between the total phenolic content and SC₅₀, but there was no significant correlation (p > 0.05) between the resveratrol content and SC₅₀ or TPC. This study could contribute to the establishment of optimal conditions for producing red wines which contain more beneficial phenolic compounds.     

Antioxidant activity of the phenolic compounds released by hydrothermal treatments of olive tree pruning

The liquors from liquid hot water treatment (LHW) and from steam explosion (SE) of Olea europea pruning were characterised for phenolic content and in vitro antioxidant activity. Rising the temperature treatment enhanced the release of phenolic compounds to the aqueous phase and the fraction of them which are soluble in ethyl acetate was increased. Up to 2.29 and 1.88 g gallic acid equivalents (GAE)/100 g pruning were solubilised in LHW and SE, respectively, 80% of these compounds were recovered in the ethyl acetate extract. Syringol and syringaldehyde were the most abundant lignin derived volatile products identified. Hydroxytyrosol, oleuropein, syringaldehyde and tyrosol were the major phenolic compounds identified by HPLC. The antioxidant activity of the extracts, comparable to that of synthetic antioxidants, depended on the extract concentration but was scarcely affected by treatment temperature.     

Changes of phenolic acids and antioxidant activities during potherb mustard (Brassica juncea, Coss.) pickling

Phenolic acids in potherb mustard (Brassica juncea, Coss.) were determined and the effects of pickling methods on the contents of total free phenolic acids, total phenolic acids, total phenolics, and antioxidant activities were investigated. Gallic acid, protocatechuic acid, p-hydroxybenzoic acid, vanillic acid, caffeic acid, p-coumaric acid, ferulic acid, and sinapic acid were identified in the present study. The contents of total free phenolic acids, total phenolic acids and total phenolics in fresh potherb mustard were 84.8 ± 0.58 μg/g dry weight (DW), 539 ± 1.36 μg/g DW, and 7.95 ± 0.28 mg/g DW, respectively. The total free phenolic acids increased during the pickling processes, but the total phenolic acids, total phenolics, and antioxidant activities decreased. However, after 5 weeks of fermentation, all the pickling methods retained over 70% of total phenolic contents and above 65% of antioxidant capacities. The results indicated that pickling processes were relatively good methods for the preservation of phenolic acids and antioxidants for potherb mustard.