Effect of rotating tray drying on antioxidant components,color and rehydration ratio of tomato saladette slices

A rotating tray drier was built and controlled for drying of tomato slices at different temperatures (45, 50 and 60 °C) and air velocities (0.6 and 1.2 m s^?1) with and without tray rotation. Drying curves were fitted using the Page mathematical model. Effective diffusivities for the different drying conditions correlated well with the chemical composition variables; lycopene, ascorbic acid and total polyphenols (TPP). The effect of drying conditions over quality of dried tomato slices was evaluated by quantifying their contents of lycopene, ascorbic acid and TPP, and measuring their color and rehydration ratio. The best drying conditions were 60 °C drying temperature and 0.6 m s^?1 air velocity with the use of tray rotation. These conditions minimized the degradation of lycopene (2.9%), ascorbic acid (17.3%) and TPP (2.1%) during drying. Tray rotation has a contribution on the a* color value, as well as on the lycopene and ascorbic acid concentrations (5% significance level).     

Antioxidant effects of rosemary extracts on sunflower oil compared with synthetic antioxidants

The antioxidant activities of ethanol extracts of rosemary (Rosmarinus officinalis L.) (RE) were tested in natural sunflower oil stored at 60 °C by measuring their peroxide values (POV), thiobarbituric acid‐reactive substances (TBARS), free fatty acid (FFA) content and p‐anisidine value (AnV) after regular intervals compared with synthetic antioxidants. After 3 weeks of storage at 60 °C, sunflower oil containing 200 mg kg^?1 rosemary extracts showed lower POVs (75.7 ± 0.47  meq kg^?1), thiobarbituric acid‐reactive substances (TBARS)(0.161 ± 0.002 μg mL^?1), FFA contents (0.45 ± 0.04 mg g^?1) and AnV (12.4 ± 0.02) than the control sample. Sunflower oil containing 200 ppm butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT) and tert‐butylhydroquinone (TBHQ) showed POVs (204 ± 0.68, 159 ± 0.55, 20 ± 0.49 meq kg^?1), thiobarbituric acid‐reactive substances (TBARS) (0.171 ± 0.002, 0.184 ± 0.002, 0.069 ± 0.001 μg mL^?1), FFA contents (0.34 ± 0.03, 0.46 ± 0.03, 0.2 ± 0.01 mg g^?1) and AnV (14.7 ± 0.03, 16.5 ± 0.04, 6.77 ± 0.01), respectively, after 3 weeks of storage at 60 °C. These results illustrate that rosemary extracts exhibited very strong antioxidant activity, almost equal to that of synthetic antioxidants (BHA and BHT).     

Chemical Composition, Antioxidant Capacity, and Sensory Quality of Pomegranate (Punica granatum L.) Arils and Rind as Affected by Drying Method

The objective of this study was to evaluate the application of: (1) freeze drying, (2) convective drying (50, 60, or 70 °C), (3) vacuum–microwave drying (240, 360, or 480 W), and (4) a combined method of convective pre-drying and vacuum–microwave finish drying in the processing of pomegranate arils and rind. The quality parameters under study included sugars and organic acids, punicalagins and ellagic acid, total polyphenols, total antioxidant activity, and sensory quality. In general, drying led to a reduction in all studied parameters; however, the behavior of arils and rind was different. Vacuum–microwave drying at 240 or 360 W was the best drying treatment for arils, while rind required freeze drying or soft conditions of convective drying (50 °C). Further research is needed to obtain proper results with convective pre-drying and vacuum–microwave finish drying of arils and rind. With proper selection of the drying protocol, high-quality dried arils will be available for consumers; these arils will be characterized by high contents of fructose (25 g 100 g^?1), phytic acid (2.2 g 100 g^?1), punicalagins (0.57 mg g^?1), total polyphenols (1.6 mg eq gallic acid g^?1), high antioxidant capacity (0.6 mg eq Trolox g^?1), and high intensities of garnet color, sweetness, sourness, and fresh pomegranate aroma. Besides, dried rind with very high contents of active compounds (123 mg g^?1 of punicalagins and 108 mg eq gallic acid g^?1) and high antioxidant capacity (26 mg eq Trolox g^?1) will be also available as functional material.     

Drying characteristics and quality of taegeuk ginseng (Panax ginseng C.A. Meyer) using far‐infrared rays

The purpose of this study is to investigate the drying characteristics of taegeuk ginseng using a far‐infrared dryer. The dryer used for this experiment can control the drying parameters such as far‐infrared heater temperature and air velocity. The far‐infrared drying tests of taegeuk ginseng were performed using large, medium and small ginseng at an air velocity of 0.6 m s^?1, and drying chamber temperatures of 45, 55 and 65 °C. The results were compared with those of the hot‐air drying method. The drying characteristics were analysed based on factors such as drying rate, colour changes, internal tissue structure of ginseng, saponin contents and antioxidant activities, and energy consumption. In general, the hot‐air drying time was 3–3.5 days longer than that of far‐infrared drying under the same conditions. The colour changes of far‐infrared drying were also smaller than that of hot‐air drying. Far‐infrared dryer required less energy consumption about 9.67–14.8% less than that required by hot‐air drying. At the same time, the saponin and polyphenol contents of taegeuk ginseng subjected to far‐infrared drying were 1.01 mg g^?1, 7.81 mg/100 g higher than that subjected to hot‐air drying, respectively. The results showed that the far‐infrared drying increases the capacity and quality of taegeuk ginseng.     

Effect of grape dietary fibre on the storage stability of innovative functional seafood products made from farmed meagre (Argyrosomus regius)

Two groups of farmed meagre (Argyrosomus regius) sausages were studied regarding quality changes and antioxidant capacity during a 98‐day storage experiment at 2 ± 2 °C. Control sausages contained 3.9% (w/w) of inner pea dietary fibre (IPDF) and the other group contained 0.9% (w/w) IPDF plus 3.0% (w/w) of antioxidant grape dietary fibre (AGDF). The control and AGDF meagre sausages presented a high nutritional value, given their low caloric content, fatty acid profile, amino acid composition and high DF content. Both products were remarkably stable over storage time. The AGDF had an effective antioxidant capacity, proven not only by the radical scavenging activity (90.0–91.0% vs. 82.1–85.4%) and reducing power (8.13–9.10 mg ascorbic acid equivalent g^‐1 vs. 4.16–4.24 mg ascorbic acid equivalent g^?1) measurements, but also by the lower thiobarbituric acid reactive species (TBARS) values (0.78–1.10 vs. 1.50–2.08 mg malonaldehyde kg^?1) over storage time. AGDF seemed to present antimicrobial effect, since on the 63rd day (beginning of significant microbial growth), the control sausages had more than 3 log CFU g^?1 and AGDF sausages much <3 log CFU g^?1. The sensory assessment pointed to some loss of textural quality, more accentuated in the AGDF sausages.     

Preparation,antioxidant activity and protective effect of coconut testa oil extraction on oxidative damage to human serum albumin

Extraction, physicochemical properties and fatty acid composition analysis of coconut testa oil (CTO), antioxidant activity and the protective effect on oxidative damage to human serum albumin (HSA) of coconut testa oil extract (CTOE) were investigated. Results showed that the optimal extract condition of CTO was B₃A₂C₂ (temperature of 60 °C, material‐to‐solvent of 1:4 g mL^?1 and extraction time of 3 h) with the maximum oil yield (76.83 ± 0.53%). The obtained CTO was nondrying oil with iodine value of 14.69 g per 100 g, and lauric acid was the main component of 42.28%. Hydrogen peroxide scavenging activity of CTOE can reach to 49.81% at 2.5 mg mL^?1, while antioxidant activity (AA) on the oxidation of linoleic acid dropped from 56.82% to 31.70% during the first 80 min. CTOE could prevent HSA from oxidative damage induced by hydrogen peroxide via inhibiting the formation of protein carbonyl and increase of hydroperoxides content effectively. Total phenolic content was 68 mg g^?1, and the epicatechin and catechin were 2.74 and 2.26 mg g^?1 in its phenolic compositions, respectively. These all suggested CTO and CTOE might be new worthy exploiting functional sources.     

Optimisation of pressurised liquid extraction for antioxidative polyphenolic compound from Momordica charantia using response surface methodology

Pressurised liquid extraction (PLE) of antioxidant compounds from bitter gourd fruits (Momordica charantia) in aqueous ethanolic solvent was investigated using response surface methodology at laboratory scale to understand key impact of extraction variables. Extraction efficiency was optimised by measuring the yield of extraction, total phenolic content (TPC), total flavonoid content (TFC), ferric reducing/antioxidant power assay (FRAP) and radical scavenging activity (RSA). The optimal extraction conditions were reached at 80% ethanol concentration, 10‐min extraction time and at 160 °C. Under these extraction conditions, values of TPC (5.40 ± 0.30 g GAE per 100 g), TFC (1.50 ± 0.10 g QE per 100 g), FRAP (778.55 ± 10 μmol eq Fe (II) g^?1), yield (178.50 ± 5.50 mg g^?1 dc) and RSA (75.50 ± 4.50%) were achieved. Furthermore, statistical analysis revealed that antioxidative attributes of bitter gourd extract were strongly and positively correlated with extraction temperature and ethanol concentration rather than processing time. This study illustrated that PLE has the potential to extract antioxidant compounds from tropical fruit vegetables in an accelerated manner. Furthermore, influential parameters affecting the process could be optimised for further industrial intake.     

Optimisation of the peracetic acid washing disinfection of fresh‐cut strawberries based on microbial load reduction and bioactive compounds retention

Total microbial count reduction (TMR), total anthocyanins (TAR), and ascorbic acid retention (AAR) after the operation at different PAA concentrations (0–100 mg L^?1), contact times (10–120 s), and temperatures (4–40°C) were used for multiple optimisation using Derringer′s desirability function. Two optimization scenarios (OP 1 and OP 2) were studied. OP 1 was proposed with the goal to maximize TMR with 90% TAR and AAR; and OP 2 maximizing TAR and AAR with TMR of 2 log UFC g^?1. The optimized variable levels obtained were the following: 100 mg L^?1 PAA, 24 °C and 50 s for OP 1 and 20 mg L^?1 PAA, 18 °C and 52 s for OP 2. Additional validation experiments showed agreement between predicted and experimental results. OP 2 conditions are recommended to fresh‐cut strawberries washing disinfection because of an acceptable TMR, higher TAR and AAR, better sensory attributes, and the economic convenience of lesser PAA consumption.     

Effect of storage on the bioactive compounds and antioxidant activity of quince nectar

The changes of bioactive components and antioxidant activity of quince nectar were determined during 9 months of storage at 5, 20, 30 and 40 °C. The amount of total phenolics, flavonoids and antioxidant activity was significantly declined during storage at all temperatures. Loss of L‐ascorbic acid at 5, 20, 30 and 40 °C was 32.08%, 43.69%, 65.21% and 88.82%, respectively. L‐ascorbic acid degradation was in accordance with the first‐order reaction kinetics, and activation energy was found as 43.65 kJ mol^?1. After 9 months of storage, Hydroxymethylfurfural (HMF) contents of quince nectars were 15.01, 16.64, 21.69 and 57.89 mg kg^?1 at 5, 20, 30 and 40 °C, respectively. HMF accumulation fitted a zero‐order kinetic model, and activation energy was found as 88.30 kJ mol^?1. A significant correlation was found among L‐ascorbic acid, total phenolics, flavonoids and antioxidant activity.     

Radical scavenging and anti‐proliferative capacity of three freeze‐dried tropical fruits

Tropical fruits are rich in antioxidant and anticancer phytochemicals, but their nutraceutical potential could be enhanced by drying technologies. Mango cv. Ataulfo, papaya cv. Maradol and pineapple cv. Esmeralda ripe pulps were freeze‐dried (?42 °C, 0.12 torr, 48 h) and their physicochemical and phytochemical profile, radical scavenging and antiproliferative capacity evaluated. The content of soluble solids, phenolic compounds and ascorbic acid was higher in mango (16.1^oBrix, 9.9 mg GAE per g and 9.6 mg g^?1) than in papaya/pineapple, but the later had more flavonoids (0.45 ± 0.05 mg QE per g). A fruit‐specific phenolic profile was detected by HPLC‐ESI‐QTOF‐MS, being shikimic (mango), chlorogenic (papaya), and protocatechuic (pineapple) acids the most abundant. Mango was the strongest radical scavenger and showed antiproliferative capacity (IC₅₀, μg mL^?1) in RAW 264.7 (100.7), HeLa (193.1) and L929 (138.5) cell lines. Papaya and pineapple extracts showed no antiproliferative activity. Freeze‐dried mango is a ready‐to‐eat functional food with better cancer preventing properties than papaya or pineapple.     

Optimisation of drying conditions for the extraction of β‐carotene,phenolic and ascorbic acid content from yellow‐fleshed sweet potato using response surface methodology

The objective of this study was to optimise drying conditions for the extractions of β‐carotene, phenolic and ascorbic content from yellow‐fleshed sweet potato using response surface methodology. A face‐centred cubic was used to investigate the effects of three independent variables namely drying temperature 55–65 °C, citric acid concentration 1–3%w/v and soaking time 1–3 min. The optimal conditions for parameters were 55–62 °C, citric acid concentration 1.08–2.19% and soaking time 1.53–2.00 min. Under the above mentioned conditions, the experimental β‐carotene content was 14.61 mg g^?1, total phenolic and ascorbic acid content were 4.0 and 17.53 mg g^?1, respectively, which were close to the predicted values. Therefore, the results showed that optimise conditions could be used to enhance the antioxidant activities of functional foods.     

Decreasing effect of fluoride content in Antarctic krill (Euphausia superba) by chemical treatments

Decreasing effects of fluoride contents in Antarctic krill (Euphausia superba) as affected by chemical treatments with and without heating were investigated. The used chemicals were NaOH, Na₂CO₃, Na₂SO₃, citric acid, acetic acid, phosphoric acid, HCl, ethanol, lysine, aminoguanidine, arginine, carnitine, betaine, and creatine. Fluoride contents per dry weight were 788 ± 10 mg kg^?1 in the whole body of krill (WBK) and 294 ± 4 mg kg^?1 in the peeled krill meat (PKM) respectively. When WBK was treated with chemicals with and without heating or thawed, fluoride was not decreased. On the other hand, when the PKM was treated with chemicals without heating was remarkably decreased to less than 100 mg kg^?1, which is the criteria recommended by FDA. Particularly, the treatment of betaine without heating showed the best reduction effect of 30 ± 6 mg kg^?1, followed by carnitine (38 ± 17 mg kg^?1), acetic acid (52 ± 1 mg kg^?1), phosphoric acid (67 ± 2 mg kg^?1) and hydrochloric acid (68 ± 1 mg kg^?1).     

Effect of pretreatments and drying temperatures on sweet potato flour

Effect of pretreatments with 1 w/v% sodium hydrogen sulphite (NaHSO₃) and 1 w/v% calcium chloride (CaCl₂) and drying temperatures (55, 60 and 65 °C) on sweet potato flour were investigated. Flour treated with CaCl₂ had higher amounts of ascorbic acid and β‐carotene (10.61–12.54 and 3.26–3.46 mg 100 g^?1 wet basis, respectively) than that treated with NaHSO₃ (9.47–11.47 and 3.05–3.43 mg 100 g^?1 wet basis, respectively). Total phenolic content and water absorption index (wet basis) were highest at 65 °C when treated with NaHSO₃ (10.44 mg 100 g^?1 and 2.49 g g^?1 respectively) and CaCl₂ (9.52 mg 100 g^?1 and 2.85 g g^?1 respectively). Swelling capacity (wet basis) was highest at 60 °C when treated with CaCl₂ (2.96 g g^?1) whereas when treated with NaHSO₃ (2.85 g g^?1) it was highest at 55 °C. Freeze‐dried samples treated with NaHSO₃ had higher lightness and total phenolic content while CaCl₂‐treated samples had higher β‐carotene and ascorbic acid. The results showed that good quality flour could be produced after soaking in CaCl₂ and dried at 65 °C.     

Experimental study on drying of pear slices in a convective dryer

The experiments were conducted on pear slices with thickness of 5 mm at temperatures of 50, 57, 64 and 71 °C with an air velocity of 2.0 m s^?1. Prior to drying, pear slices were pretreated with citric acid solution (0.5% w/w, 1 min, 20 °C) or blanched in hot water (1 min, 85 °C). Also, the untreated samples were dried as control. The shortest drying time of pear slices was obtained with pretreatment with citric acid solution. It was observed that whole drying process of pear slices took place in a falling rate period. Four mathematical models were tested to fit drying data of pear slices. According to the statistical criteria (R², χ² and RMSE), the Midilli et al. model was found to be the best model to describe the drying behaviour of pear slices. The effective diffusivity of moisture transfer during drying process varied between 8.56 × 10^?11 and 2.25 × 10^?10 m² s^?1, while the activation energy of moisture diffusion in pear slices was found to be 34.95–41.00 kJ mol^?1.     

Quantitative UPLC‐MS/MS analysis of chlorogenic acid derivatives in antioxidant fractionates from dandelion (Taraxacum officinale) root

While qualitative studies have identified chlorogenic acids in antioxidant extracts, particularly ethyl acetate‐derived extracts, of Taraxacum officinale, quantitative analysis of these phenolic compounds remains largely unreported for this species. In this study, bioactivity‐guided fractionation of an antioxidant crude ethyl acetate extract (DPPH = 295.481 ± 0.955 mg TE g^?1 extract) from T. officinale root resulted in a number of reverse‐phase fractions that demonstrated high antioxidant activity (DPPH = 1058.733–1312.136 mg TE g^?1 extract), stronger than that of the synthetic antioxidant Trolox^®. UPLC‐MS/MS screening of these fractions for the presence of selected mono‐ and di‐caffeoylquinic acids revealed large quantities of 1,5‐dicaffeoylquinic acid present in several fractions (853.052–907.324 μg mg^?1), respectively. Due to the antioxidant potency and high levels of 1,5‐dicaffeoylquinic acid observed in these fractions, it was concluded that specifically this chlorogenic acid derivative is a major contributor to the antioxidant efficacy of dandelion root.     

Production,iron analysis and consumer perception of functional Thai Sinlek iron rice (Oryza sativa) drink

We produced the iron rice (IR) drink, determined the relevant chemical composition and antioxidant activity and tested the consumers’ degree of satisfaction. IR grains were digested with α-amylase and analysed chemical composition and antioxidant activity, while the hydrolysate (pH 4.0) and flavouring agents were added for final preparation of the IR drink. The IR hydrolysate contained a total iron content of 13.9 mg g⁻¹, a total phenolic content of 1.33 ± 0.07 mg gallic acid equivalent g⁻¹ and γ-oryzanol of 70.12 ± 2.7 mg kg⁻¹ rice grain, all of which inhibited the generation of free radicals in a concentration-dependent manner. The IR drink was composed of flavonoids and phenolic acids for which kaempferol was predominant. The members of all three groups of elderly subjects who consumed the low-dose IR (1.47 mg iron/100 mL), high-dose IR (2.74 mg iron/100 mL) and white rice (WR; 0.5 mg iron/100 mL) drinks expressed satisfaction and interest with the beverages at 91.2%, 100% and 88.9%, respectively. In terms of sensory evaluation, the low-dose IR drink revealed a higher acceptance rating than high-dose IR and WR (P < 0.05). Notably, the Sinlek rice drink was abundant with iron, anti-oxidative phenolics and γ-oryzanol, for which consumers expressed an overall degree of acceptance (8.1 ± 1.1).     

Watermelon juice pretreatment with microfiltration process for obtaining lycopene

The aim of this study was to evaluate the effect of microfiltration on the lycopene content and antioxidant capacity of watermelon juice using ceramic membranes with an average pore size of 0.1 μm and a permeable area of 0.022 m². The influence of the tangential cross‐flow velocity (4.3–6.4 m s^?1) and temperature (23–37 °C) on the permeation flux, lycopene content and antioxidant capacity was evaluated. A 2² complete factorial experimental design was used. Increases in tangential cross‐flow velocity and temperature had positive effects on permeation flux, with a maximum of 92.4 l h^?1 m^?2 achieved at 6.4 m s^?1 and 30 °C. With regard to the lycopene content and antioxidant capacity, tangential cross‐flow velocity was the only factor that exhibited significant effects on these responses. For the most concentrated extract, the lycopene concentration and antioxidant capacity were enhanced by 402.8% and 416.3%, respectively.     

Characterisation of osmotically dehydrated papaya with further hot air drying and microwave vacuum drying

Papaya was subjected to osmotic dehydration (OD) prior to hot air drying (HA; 70 °C) and microwave vacuum drying (MVD; 3.75 W g^?1 and 13.3 kPa). An increase in immersion time in a sucrose solution [65/100 g (w/w)] at 40 ± 2 °C from 0 to 4 h decreased moisture content from 7.5802 to 1.2215 kg water kg dry solid^?1. During HA and MVD, effective moisture diffusivity was in the range 7.09 × 10^?8 to 9.13 × 10^?8 m² s^?1 and 2.85 × 10^?6 to 3.50 × 10^?6 m² s^?1, respectively, depending on immersion time. The hue angle of HA samples was 0.83–0.91, whereas that of MVD samples was 48.55–50.32. Both drying methods decreased springiness. Porosity was clearly observed in MVD samples. Rehydration rate was enhanced by increased immersion time and MVD (P ≤ 0.05). From preference mapping, MVD samples were more preferable than HA samples. Moreover, MVD samples with 1–3 h OD were more preferable than those with 4 h OD.     

The antioxidant activities and the xanthine oxidase inhibition effects of walnut (Juglans regia L.) fruit,stem and leaf

The antioxidant activities and xanthine oxidase inhibition effects of walnut fruit, stem and leaf were studied in this work. The total phenolic contents were in a descending sequence: shell extract > leaf extract > stem extract > defatted walnut kernel (DWK) extract > green husk extract (GHE). The sequence of total phenolic contents was in agreement with the sequence of antioxidant capacities evaluated by ferric reducing antioxidant power and oxygen radical absorbance capacity (ORAC) assays except for DWK extract. The walnut shell extract showed the highest phenolic content (14.81 gallic acid equivalent g/100 g dry extract) and the best antioxidant activity (the ORAC value was 3423.44 ± 142.52 μmol Trolox equivalents g^?1). All tested samples possessed xanthine oxidase inhibitory (XOI) effects, the inhibition percentages of which were >50% at 2 mg mL^?1 except for stem and DWK extracts. The contents of the major compound (hydrojuglone) in all extracts were in a descending order: GHE > walnut stem extract > walnut shell extract > walnut leaf extract > DWK extract.     

Hypolipidaemic and antioxidant capacities of polysaccharides obtained from Laminaria japonica by different extraction media in diet‐induced mouse model

This study shows the industrial feasibility of using aqueous methods to produce antioxidative and hypolipidaemic polysaccharides from Laminaria japonica (LJP). Comparison was firstly made among the polysaccharides prepared using different extraction media, that is water alone (LJPW) and citric acid (LJPC), sulphuric acid, hydrochloric acid and phosphoric acid. LJPC enabled the highest extract yield (~11% dry weight), bile salt adsorption rate (~59% dry weight), ABTS radical scavenging activity (IC₅₀ value 1.06 mg mL^?1) and ORAC antioxidant activity (341.87 μmol Trolox g^?1). In animal trial using diet‐induced high‐fat mice, oral administration of LJP produced with citric acid (LJPC) at a high dose (200 mg kg^?1 body mass per day) enabled significantly higher serum HDL‐C, lower LDL‐C/HDL‐C and unaltered LDL‐C, whilst a medium dose (100 mg kg^?1 body mass per day) significantly decreased LDL‐C. Administration of LJP produced with water (200 mg kg^?1 body mass per day) significantly lowered serum LDL‐C. Therefore, LJP may provide dose‐dependent pharmacological and therapeutic effects to combat atherosclerosis through their hyperlipidaemic and antioxidant properties.