•US-CD significantly improved antioxidant capacity and total phenolic content of dried apples.•US-CD reduced drying time by nearly 45% compared to traditional hot air drying (HAD).•US-CD reserved the ...micro-structure of the dried apples better than the HAD samples.•US-CD samples had improved rehydration ratio, color, and textural properties compared to the HAD treatment.
Drying is one of the most prevalent methods to reduce water activity and preserve foods. However, it is also the most energy-intensive food processing unit operation. Although a number of drying methods have been proposed and tested for the purpose of achieving a time- and energy-efficient drying process, almost all current drying methods still rely on thermal energy to remove moisture from the product. In this study, a novel use of power ultrasound was explored for drying of apple slices without the application of heat. The non-thermal ultrasound contact drying (US-CD) was performed in the presence of an air stream (26–40 °C) flowing over product surface to remove mist or vapor produced by the ultrasound treatment. The effects of the non-thermal US-CD, hot-air drying (HAD), and freeze drying (FD) on the changes in rehydration ratio, pH, titratable acidity, water activity, color, glass transition temperature, texture, antioxidant capacity, total phenols, and microstructures of the samples were evaluated. The moisture content of the apple slices reached below 5% (w.b.) after 75–80 min of US-CD, which was about 45% less than that of the HAD method. The antioxidant capacity and total phenol contents of the US-CD samples were significantly higher than that of the AD samples. The non-thermal ultrasonic contact drying is a promising method which has the potential to significantly reduce drying time and improve product quality.
•Chitosan coating @ 2% was applied on ‘Santa Rosa’ plums for extension of the storage life.•Physical, physiological and chemical attributes were recorded at 7days interval.•Chitosan coating ...effectively maintained quality and enhanced the storage life of plums up to 35days at 1±1°C.
The effect of chitosan coating on the storage life and quality of ‘Santa Rosa’ plum was investigated. The plum fruits were treated with 2% chitosan coating and stored at 1±1°C under 90±5% RH. During storage, observations on weight loss, fruit firmness, colour, rates of respiration and ethylene evolution, biochemical and quality attributes were recorded at weekly interval. Our experiment yielded that chitosan had a significant effect in maintaining fruit firmness (∼78%), retarding weight loss (∼52%), respiration and ethylene evolution rates and delaying the colour change as compared to non-coated fruits. Furthermore, at the end of 35days of storage at low temperature, a significant reduction in pectin methylesterase activity (∼44%) and malondialdehyde production (∼21%) was observed. Similarly, anthocyanin content (∼24%) was significantly retarded in chitosan-coated ‘Santa Rosa’ plums. Thus, postharvest application of chitosan as an edible coating can effectively maintain the quality and extend the storage life of plum up to 35days under low temperature storage condition.
This study was aimed to evaluate the effects of germination process on melatonin, total phenols, total flavonoids and antioxidant activities of broad beans (Vicia faba L.), lupine seeds (Lupinus ...albus), chickpea seeds (Cicer arietinum L.), lentil seeds (Lens culimaris), fenugreek seeds (Trigonella foenum-graecum L.) and common beans (Phaseolus vulgaris) fractions (cotyledons, radicles and seed hulls). Radicle length of germinated legumes and sensory properties of legumes after 6days of germination were also evaluated. Fenugreek and chickpea seeds had higher melatonin (54.22 and 24.42ng/g), total phenols (5.79 and 5.68mg gallic acid/g) and total flavonoids (8.86 and 8.43mg quercetin/g), respectively than other legumes however, common beans showed the lowest values. Broad beans and lentil seeds had the highest antioxidant activities while lupine seeds showed the lowest value among all other legumes. The mean values of melatonin for cotyledons, radicles and seed hulls were increased by 386.26, 261.98 and 183.22%, respectively compared with the third day of germination. The increases in melatonin content of legume fractions were parallel to the increases in radicle lengths, total phenols, total flavonoids and antioxidant activities throughout the germination time. Overall acceptability of legumes had rating scores ranged between like moderately and like very much except for chickpea which had rating score described as like slightly.
Narcissus tazetta plant from Amaryllidaceae family is known to be rich in bioactive metabolites such as Alkaloids, phenolics and flavonoid which detected in almost species of this family. N. tazetta ...cultivated in Iraq, had not yet been studied for its active components as antimicrobial; thus the current study employed the antibacterial activity for total phenolic compounds and total alkaloids extracted from this plant. The plant bulb pieces were defatted with n-hexane before extraction of total phenols(TP) and total alkaloids(TA) from the plant. Results showed that the plant contains about 0.95g/140g bulb as total phenols residue and 0.7g/150g bulb as total alkaloids residue. The major Tp compounds observed in HPLC assay were Salycilic acid, Sinapic acid, vanillic acid, Caffeic acid, Chlorogenic acid, and p-coumaric acid in desending quantity. Four layer had been collected that might contain different kinds of alkloids. The methanolic layer (1) and layer (3) which represented the chloroform layer after acidification represented the richest layers in 'Glanthamine' alkloid represented by HPLC assay. The antibacterial as inhibitory effects of TP and TA on E.coli, P.auroginosa, S.aureus and Bacillus subtillus, showed moderate antibacterial activity for both plant extracts in coparisin to some trade antibiotics.
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► Walnut green husk (WGH) is an abundant agro-forest by-product without economic value. ► It could be explored as source of bioactive compounds. ► Extraction solvent influences ...composition and activity of WGH extracts. ► WGH extracts showed high antioxidant and antimicrobial potential. ► WGH proved to be a cheap source of bioactive properties for food, cosmetic or pharmaceutical industries.
Walnut green husk is an agro-forest waste generated in the walnut (Juglans regia L.) harvest that could be valued as a source of natural compounds with antioxidant and antimicrobial properties. At this respect, the effect of the solvent (water, methanol, ethanol and 50% aqueous solutions of methanol and ethanol) on the extraction yields and extracts bioactive properties was analysed. Total phenols content of the extracts was determined by the Folin–Ciocalteau method. Extract antioxidant activity was evaluated using the reducing power assay and by the ability of the extracts to scavenge the DPPH radical. The scavenging effect of the aqueous extracts on the nitric oxide radical was also evaluated. The highest extraction yield was achieved with water (44.11%) and high bioactive potential was shown by the samples extracted with water/ethanol (1:1) (84.46mg GAE/g extract; EC50=0.95mg/mL for reducing power and EC50=0.33mg/mL for DPPH assay). All the antioxidant properties analysed showed a concentration-dependent activity. The antimicrobial activity of the aqueous extracts was assessed and showed ability to inhibit the growth of Gram positive bacteria. The results obtained demonstrated the potential of the walnut green husk as an economical source of antioxidant and antimicrobial agents.
Boron (B) toxicity is an important abiotic constraint that limits crop productivity mainly in arid and semi-arid areas of the world. High levels of B in soil disturbs several physiological and ...biochemical processes in plant. The aim of this study was to investigate the function of melatonin (Mel) in the regulation of carbohydrate and proline (Pro) metabolism, photosynthesis process and antioxidant system of wheat seedlings under B toxicity conditions. High levels of B inhibited net photosynthetic rate (PN), stomatal conductance (gs), content of chlorophyll (Chl) a, b, δ-aminolevulinic acid (δ-ALA), nitrogen (N) and phosphorus (P), and increased accumulation of B, Chl degradation and activity of chlorophyllase (Chlase; a Chl degrading enzyme), and downregulated the activity of enzymes (δ-ALAD; δ-aminolevulinic acid dehydratase) involved in the biosynthesis of photosynthesis pigments, photosynthesis (carbonic anhydrase and ribulose-1,5-bisphosphate carboxylase/oxygenase) and carbohydrate metabolism (cell wall invertase, CWI) in wheat seedlings. Also, high levels of B caused oxidative damage by increasing the content of malondialdehyde, superoxide anion and H2O2, and activity of glycolate oxidase (an H2O2-producing enzyme) in leaves of seedlings. However, foliar application of Mel significantly improved photosynthetic pigments concentration by increasing δ-ALA, δ-ALAD and decreasing Chl degradation and Chlase activity and led to an increase of plant growth attributes under both B toxicity and non-toxicity conditions. Under normal and B toxicity conditions, exogenous Mel also improved content of N, P, total soluble carbohydrates (TSCs) and Pro, and upregulated activity of CWI and Δ1-pyrroline-5-carboxylate synthetase. Mel significantly suppressed the adverse effects of excess B by alleviating cellular oxidative damage through enhanced reactive oxygen species scavenging by superoxide dismutase, catalase, ascorbate peroxidase, glutathione reductase and lipoxygenase, and content of total phenolic compounds (TPC), ascorbate and reduced glutathione. These results postulate that Mel induced plant defense mechanisms by enhancing Pro, TSCs, TPC, nutrients (N and P) uptake and enzymatic and non-enzymatic antioxidants.
Schematic diagram of melatonin induced resistance against B-toxicity by regulating antioxidant system, carbohydrate metabolism, proline and photosynthetic pigments biosynthesis in wheat seedlings. RuBisco—ribulose-1,5-bisphosphate carboxylase/oxygenase, CWI—cell wall invertase, ROS—reactive oxygen species, Chlase— Chlorophyllase, GOx—glycolate oxidase, CO2—carbon dioxide, Ch—chlorophyll, CA—carbonic anhydrase, and δ-ALAD—δ-aminolevulinic acid dehydratase, δ-ALA—δ-aminolevulinic acid, Pro—proline, P5CS—Δ1-pyrroline-5-carboxylate synthetase activity, LOX—lipoxygenase, TPC—content of total phenolic compounds, ASC—ascorbate, GSH—reduced glutathione, SOD—superoxide dismutase, GR— glutathione reductase, APX—ascorbate peroxidase, and GR—glutathione reductase. Display omitted
•Boron toxicity impairs growth, Chl biosynthesis, photosynthesis process, and metabolism of TSCs and Pro.•High levels of boron enhances ROS, MDA and glycolate oxidase activity.•Melatonin suppresses boron toxicity-induced oxidative damage.•Melatonin regulates antioxidant metabolism, and modulates TSCs and Pro metabolism.•Melatonin maintains nutrients homeostasis in of plant under boron toxicity.
Chocolates are considered functional foods and are consumed worldwide. The objective was to evaluate the effect of particle size and the inclusion of Physalis peruviana L (Goldenberry) and Vaccinium ...spp (Andean blueberry) on sensory attributes, color, total phenols, and anthocyanins in dark and milk chocolate. The attributes of gloss, surface, breakage, melting, grittiness, odor, fruit scents, aftertaste, sweetness, mouthfeel, bitterness, and astringency were evaluated for sensory evaluation. To measure color, the CIELAB system was used. Phenols were evaluated using spectrophotometry and anthocyanins using the pH differential method. According to principal components analysis (PCA), dark chocolates with the inclusion of goldenberries had the best sensory scores (Øp =10-20 µm); the results for the correlations were 0.97 for surface and melting, 0.98 for surface and aftertaste, 1.0 for aftertaste and astringency, and -0.92 melting and odor. Milk chocolate with the inclusion of goldenberries (Øp =10- 20 µm) was superior in attributes such as fruit scents, sweetness, grittiness, gloss, odor, aftertaste, and mouthfeel. At the same time, there was a correlation between melting and aftertaste of -0.92 and between melting and mouthfeel of -0.94, odor with fruit scents and sweetness were 0.96 and 0.98, and fruit scents with aftertaste and sweetness were 0.94 and 0.99. Dark and milk chocolates with the inclusion of goldenberries (Øp =10-15 µm) were slightly superior in the phenol content, while chocolates with the inclusion of Andean blueberries (Øp =10-20 µm) had greater anthocyanin contents.
In this research, the effect of acai pulp on the physicochemical, sensory quality, and antioxidant capacity of a type II yogurt sweetened with Stevia was evaluated. A completely randomized ...experimental design with a factorial arrangement was proposed, the factor under study corresponded to the concentrations of 5, 10 and 15% of acai pulp. Three replicates per formulation trial were established respectively. The Tukey test was used for the physicochemical and antioxidant capacity variables, while the KruskalWallis test was used for the sensory profile. A significant difference was determined in the study variables and the following results were obtained: pH 3.78 -3.79; °Brix 6.53 –7.03%; acidity 0.90 –1.02%; density 1,036 –1,039 g/ml; total solids 11.93 –12.05%; viscosity of 291.67 –382.67 mPa.s; protein 2.43 –2.49%; fat 1.27 –1.57%; total phenols 635.80 –2002.04 mg EAG/mL; antioxidant capacity 0.55 –1.84 μmol EQ Trolox/mL; the test with the best sensory acceptance was A3 (15% acai pulp) which obtained a significant difference in the flavor and texture attribute, in addition, it presented better values in colorimetry in terms of Lightness 74.87, saturation 2.47 and tone 19.30. Except for the protein content, all the treatments presented microbiological and physicochemical quality within the requirements of the INEN 2395 standard, on the other hand, the proposed hypothesis was accepted since all the evaluated parameters varied significantly in the proposed formulations. Yogurt with acai pulp can be considered a food with potential functional compounds for the benefit of the consumer.
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