Extraction and in vitro antioxidant capacity evaluation of phenolic compounds from pigmented aromatic rice (<Emphasis Type="Italic">Oryzae sativa</Emphasis> L.) cultivars

The aroma generating volatile components profile and in vitro antioxidant capacities of different aromatic rice cultivars was determined by GC–MS analysis and in terms of DPPH scavenging activity, lipid peroxidation inhibition, phosphomolybdenum reduction and reducing power assay. The total phenolic content including both free and bound forms in the analyzed aromatic rice cultivars, Mushki budgi (1.62 mg GAE/g), Mushki kandi (1.63 mg GAE/g) and Kamad (1.60 mg GAE/g) were found double the amount as compared to non-aromatic Koshkari (0.86 mg GAE/g) cultivar. The aromatic rice cultivars had also shown higher total flavonoid content and antioxidant activity than non-aromatic rice cultivar (Koshkari). The GC–MS results indicated 21-aromatic compounds present in sufficient quantities in aromatic cultivars and some of them were unique to these cultivars. Among the compounds identified, aldehydes were found in higher quantity followed by alkanes, ketones and esters. Among the aromatic rice cultivars, Mushki budgi and Mushki kandi were found possessing higher quantity of flavoring components such as benzaldehyde, a carcinostatic agent. The cultivars Mushki budgi and Mushki kandi indicated positive correlation of TPC, TFC and the in vitro antioxidant components largely, while the less aromatic Kamad, correlate with only two components viz DPPH and lipid peroxidation.     

Application of Near-Infrared Hyperspectral Imaging with Variable Selection Methods to Determine and Visualize Caffeine Content of Coffee Beans

Hyperspectral imaging covering the spectral range of 874–1734 nm was used to determine caffeine content of coffee beans. Spectral data of 958.24–1628.89 nm were extracted and preprocessed. Partial least squares regression (PLSR) model on the preprocessed full spectra obtained good performance with coefficient of determination of prediction (R ² _p ) of 0.843 and root mean square error of prediction (RMSEP) of 131.904 μg/g. In addition, 10 variable selection methods were applied to select the best optimal wavelengths. The PLSR models on the different optimal wavelengths obtained satisfactory results. The PLSR model on the wavelengths selected by random frog (RF) performed the best, with R ² _p of 0.878 and RMSEP of 116.327 μg/g. The RF wavelength selection combined with the PLSR model also achieved satisfactory visualization of caffeine content between different coffee beans. The overall results indicated that optimal wavelength selection was an efficient method for spectral data preprocessing, and hyperspectral imaging was illustrated as a potential technique for real-time online determination for caffeine content of coffee beans.     

Response surface optimization of conditions for debittering of white mahlab (<Emphasis Type="Italic">Prunus mahaleb</Emphasis> L.) juice using polystyrene resins

In the current study, debittering of white mahlab (Prunus mahaleb L.) juice using polystyrene resins was investigated and optimized using the Box–Behnken response surface methodology. The effects of independent variables including resin type (cation exchange resin, anion exchange resin, and 50:50 cation/anion exchange resin), resin dosage (0.05, 0.075, and 0.1 g/mL) and agitation speed (50, 150, and 250 rpm) on total phenolic content, total flavonoid content, total anthocyanin content (TAC), antioxidant activity, and bitterness of white mahlab juice were studied. Effects of resin type and dosage were found to be significant (p < 0.05) for all responses. A dosage of 0.05 g/mL of the anion exchange resin and an agitation speed of 250 rpm were selected as the optimum conditions based on minimum bitterness (2.42) and maximum TAC (0.018 g/mol). We could conclude that the anionic resin can greatly reduce the intensity of bitterness and maintain the composition and characteristics of the P. mahaleb juice.     

Effect of <Emphasis Type="Italic">Lactobacillus acidophilus</Emphasis> Bauer and <Emphasis Type="Italic">Bifidobacterium animalis</Emphasis> ssp. <Emphasis Type="Italic">lactis</Emphasis> BB12 on proteolytic changes in dry-cured loins

The effect of the potentially probiotic bacteria strain of Lactobacillus acidophilus Bauer and probiotic bacteria Bifidobacterium animalis ssp. lactis BB12 on proteolytic changes of proteins in dry-cured loins during fermentation and cold storage was studied. Results of the conducted tests demonstrated that the use of probiotic bacteria for the production of dry-cured meats impacts the generation of products of protein proteolysis with high antioxidant activity. The highest antioxidant activity of peptides after fermentation and cold storage was observed in the loin with the strain B. animalis ssp. lactis BB12 and the loin with the mixture of strains L. acidophilus Bauer and B. animalis ssp. lactis BB12. Qualitative analysis of peptides demonstrated that peptides with weight below 3.5 kDa are characterized by the highest capacity of quenching the ABTS cation radical, including the peptides in loins with the strain B. animalis ssp. lactis BB12.     

Influence of keeping system on the fatty acid composition in the <Emphasis Type="Italic">longissimus</Emphasis> muscle of bulls and odorants formed after pressure-cooking

German Simmental bulls were kept either in a stable (group 1) or on a pasture (group 2). For both groups the intramuscular fat content of the longissimus muscle and the fatty acid composition in phospholipids and triacylglycerols were investigated. Significant influences of feeding were shown in most fatty acids measured in both lipid classes. In concentrate-fed bulls a higher content of linoleic acid (C18:2n-6) was detected, corresponding to the large amount of linoleic acid found in concentrate used as feed. In contrast, bulls fed grass proved to have a higher linolenic acid (C18:3n-3) content, also correlating well with the larger amount of linolenic acid found in grass. Pressure-cooking of the beef followed by an analysis of eight important meat odorants revealed that, in line with the higher concentrations of the precursor fatty acids C18:3n-3 and C18:1 in muscle of group 2, (E,Z)-2,6-nonadienal (from C18:3n-3) as well as nonanal and octanal (from C18:1) were much higher in the processed meat of animals fed grass. On the other hand, the much higher amounts of C18:2n-6 in bulls fed concentrate were well-reflected by higher concentrations of five aroma compounds known to be formed by a thermal degradation of this acid, e.g. (E,E)-2,4-decadienal.     

Effect of heat-treated <Emphasis Type="Italic">Nuruk</Emphasis> on the quality characteristics of aged <Emphasis Type="Italic">Yakju</Emphasis>

Long-term aging of Yakju, a traditional Korean liquor made of rice and Nuruk (a fermentation agent), causes browning and odor and flavor development. This study investigated the effects of heat-treated Nuruk (50–80 °C, 30 min) on Yakju quality. The saccharogenic powers and glucoamylase, α-amylase, and carboxypeptidase activities were similar in non-heat-treated Nuruk and that treated at 50 °C. However, acidic protease and alcohol dehydrogenase decreased above 50 °C. The content of nitrogen-containing compounds was inversely proportional to the heat-treatment temperature. Compounds that cause off-flavors decreased at 50–60 °C, but increased at 70–80 °C, whereas compounds that provide fragrance increased at 50–60 °C. Sensory evaluation indicated that bad taste attributes were higher in Yakju produced using non-heat-treated Nuruk. Therefore, heat treatment of Nuruk at 50 °C can be adopted as a method for improving Yakju quality, as enzymatic activities that affect color, aroma, and taste are regulated.     

Effect of different drying methods on the essential oil yield,composition and antioxidant activity of <Emphasis Type="Italic">Origanum vulgare</Emphasis> L. and <Emphasis Type="Italic">Origanum onites</Emphasis> L.

Origanum onites and Origanum vulgare are important medicinal plants because of their flavoring, therapeutic, and preservative properties. Drying methods are important for obtaining high quality essential oil from spices. In this study, the effects of different drying processes on the essential oil yield, composition, and antiradical activity were evaluated. Plants were dried under sun light, in a ventilated shady place and in laboratory-type oven, and the oils were extracted with Clevenger type apparatus. Carvacrol and thymol were the major compounds in the essential oils of O. vulgare and O. onites, respectively. The highest oil yield and the highest antioxidant activity values were obtained from shade dried Origanum species followed by oven dried plants. The lowest essential oil yield and the lowest antioxidant activity for O. vulgare were found in fresh plants. The lowest essential oil yield, and the lowest antioxidant activity for O. onites belonged to sun dried plants. It could be concluded that essential oil yield, oil composition and antioxidant activity of both plants were greatly affected by the drying method.     

Effects of gardenia seed,green tea,and cactus pear in rice batter on the chemical quality of lotus root <Emphasis Type="Italic">bugak</Emphasis> and frying oil

This study investigated the effects of the addition of gardenia seed, green tea, or cactus pear (Opuntia ficus-indica) to rice batter at 10% on the lipid oxidation, pigments, antioxidants, and antioxidant activity of lotus root bugak and frying oil. Lipid oxidation was evaluated based on the conjugated dienoic acid and p-anisidine values. Lipid oxidation and tocopherol degradation were significantly reduced in the gardenia seed-added bugak and frying oil, whereas the cactus pear-added bugak and frying oil showed an increase. The addition of green tea had no significant effects on the lipid oxidation of bugak and frying oil. The in vitro antioxidant activity of lotus root bugak significantly increased with the addition of gardenia seed, green tea, or cactus pear. The results suggested that green tea and gardenia seed could improve the health and food functionality of antioxidation for lotus root bugak, respectively.     

Integrated Analytical Methods to Characterize Lipids from <Emphasis Type="Italic">Prosopis</Emphasis> spp. and <Emphasis Type="Italic">Ceratonia siliqua</Emphasis> Seed Germ Flour

Flour from seed germ of European carob (Ceratonia siliqua) and South American algarrobo (Prosopis spp.) is a potential ingredient for health-promoting baked products. Herein, lipids from germ of three Argentinean Prosopis (P. alba, P. nigra, and P. ruscifolia) and one European carob species were characterized in detail, exploiting an array of up-to-date analytical techniques. Total lipids ranged from 7.1 to 8.1% (w/w). Linoleic acid (C18:2, ω-6) predominated the GC flame ionization detector profiles of fatty acid in all samples (43.3–50.6%). Prosopis spp. contained 6–7% of C20–C24 fatty acids and, consistently, C56–C60 triacylglycerols, as detected by MALDI-TOF mass spectrometry (MS), which were practically missing in C. siliqua germ. Phospholipids were isolated by hydroxyapatite chromatography, characterized by MALDI-TOF MS and grossly quantified by attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy. Because of a relatively high content (9.5–11.8%, v/v), phospholipids might increase the antioxidant potential and improve the baking performances of flour fortified with carob and algarrobo seed germ.     

Effect of drying methods on physico-chemical properties and antioxidant activity of <Emphasis Type="Italic">Dendrobium officinale</Emphasis>

The present study aimed to investigate the effect of different drying methods, i.e., sun drying (SD), hot air drying (AD), vacuum drying (VD), infrared radiation drying (IR), and freeze drying (FD) on the physico-chemical properties of Dendrobium officinale. The results revealed that different drying methods showed significant differences in the color retention, water soluble polysaccharide content, total phenolic content, total flavonoid content, fatty acids, and antioxidant activities. FD, VD, IR and AD led to higher retention of bioactive compounds and better antioxidant activities, and FD showed the best. However, with respect to the water-soluble polysaccharides content, the characteristic components in D. officinale, AD was better than FD. The results showed that the quality of D. officinale depends on the drying method applied. Considering the retention of polysaccharide content and drying processing duration, AD is a promising treatment for D. officinale.     

Chemical composition,antioxidant, and enzyme inhibitory activities of the essential oils of three <Emphasis Type="Italic">Phlomis</Emphasis> species as well as their fatty acid compositions

This study aimed to investigate the chemical composition, antioxidant, and enzyme inhibitory activities of the essential oils of Phlomis armeniaca WILLD., P. nissolii L., and P. pungens WILLD. var. pungens as well as their fatty acid contents. Germacrene D was found as the major compound in the oils (24.7, 15.1, and 7.2%, respectively). Additionally, n-hexadecanoic acid, hexahydrofarnesyl acetone, β-caryophyllene, and linalool were the other main compounds in the oils. Among the fatty acids, C18:3 ω3 and C18:2 ω6 were determined in high quantities in P. armeniaca (23.14 and 18.01%, respectively) and P. pungens var. pungens (24.64 and 17.51%, respectively). The essential oils of P. armeniaca and P. pungens var. pungens showed remarkable antioxidant and metal chelating activities as well as great reducing power potentials. These oils also showed a moderate scavenging effect on ABTS radicals. The oils also exhibited various degrees of inhibitory activities on AChE, BChE, α-amylase, α-glucosidase, and tyrosinase.     

Development of a cooked rice model for bibimbap and resulting physico-digestive properties

A cooked rice model for bibimbap was developed using response surface methodology (RSM). The ratio of brown rice (X ₁), high amylose rice (X ₂) based on a white rice ratio of 1.0, and the ratio of water to total rice weight (X ₃), were independent variables. Stickiness (Y ₁), elasticity (Y ₂), and overall acceptability by sensory testing (Y ₃) of cooked rice were dependent variables. Optimal RSM conditions were white rice:brown rice:high amylose rice=1:1.07:0.56, and the ratio of water to total rice weight was 1.6. Coefficient of determination (R ²) values of response surface equations were 0.909, 0.930, and 0.956 for Y ₁, Y ₂, and Y ₃, respectively (p<0.05). Experimental values measured under optimal conditions coincided with predicted values. Rapidly digestive starch (RDS) and expected glycemic index (eGI) values determined using the optimized rice model were much lower than for control white rice only.     

Changes in the antioxidant capacity and phenolic compounds of <Emphasis Type="Italic">maesil</Emphasis> extract during one-year fermentation

This study aimed to identify the effects of soaking time and fermentation temperature and period on the total phenolics, total flavonoids, and antioxidant activity of maesil extract. Green maesil fruits were fermented with brown sugar at 15 or 25°C for one year. After soaking maesil for 90 days, the fruits were removed and the remaining liquid was further ripened for 275 days, whereas other samples continued to ferment with maesil until 365 days. Total phenolics, total flavonoids, and antioxidant activities of the extracts fermented with maesil for one year were higher compared with those wherein the fruits were removed at day 90. The total phenolic and total flavonoid contents were relatively higher at 15°C, whereas the ABTS and ferric-reducing antioxidant power (FRAP) activities were significantly higher at 25°C. The total phenolic and total flavonoid contents highly correlated with the antioxidant activities. These results show that fermentation temperature plays a critical role in enhancing the phenolic compounds and antioxidant activity of maesil extract.     

A comparative study on cytotoxicity and antiproliferative activities of crude extracts and fractions from Iranian wild-growing and cultivated <Emphasis Type="Italic">Agaricus</Emphasis> spp.

Little is known about anticancer capability of wild-growing mushrooms belonging to Agaricus spp. in comparison with their cultivated counterparts. The present study was done to evaluate in vitro antiproliferative effects of dichloromethane-methanol (1:1, v/v) extracts obtained from several Iranian wild strains of Agaricus spp. in comparison with the cultivated white button mushroom, A. bisporus. The wild brown A. bisporus at 500 µg/mL moderately prevented the growth of human prostate cancer (PC3) and human breast cancer (MCF-7) cell lines by 23.54 and 24.57%, respectively, while the wild strains of A. devniensis and A. gennadii at 500 µg/mL had only marginal inhibitory effects. On the contrary, the cultivated A. bisporus significantly inhibited the cell growth at concentrations as low as 125 µg/mL (p?<?0.05). Further, seven distinct fractions were determined based on thin layer chromatography analysis of the cultivated A. bisporus extract. The only active fraction was found to be eluted by petroleum ether (PE):ethyl acetate (EtOAc) (3:2 v/v) which prevented the growth of MCF-7 and PC3 by 74.00 and 63.5%, respectively at 500 µg/mL. Besides, the fraction imposed obvious cytopathic effects in both cell lines at all the tested concentrations, starting from 125 µg/mL. The findings of this study may validate that the known antioxidant potency of wild Agaricus spp. would not necessarily be correlated to their anticancer activity. This research further validated that some semi-polar antiproliferative compounds could be present in the PE/EtOAc-fraction of the cultivated white button mushroom, which warrants further investigations.     

Rapid Determination of Antioxidant Compounds and Antioxidant Activity of Sudanese Karkade (<Emphasis Type="Italic">Hibiscus sabdariffa</Emphasis> L.) Using Near Infrared Spectroscopy

The extraction conditions applied in destructive analysis of Hibiscus sabdariffa L. (Hs) matrices before the measurement of antioxidant compounds may reduce their activities during isolation and purification due to decomposition. Hence, near infrared spectroscopic system was applied to determine these compounds. The calibration models developed by using partial least squares regression (PLSR) with 48 Hs samples and 24 unknown samples were used to confirm the robustness of the developed model. The results of calibration models effectively allowed the determination of the concentrations of total phenol content (TPC), total flavonoid content (TFC), total antioxidant content (TAC), ferric reducing antioxidant power (FRAP), and 1,1-diphenyl-2-picrylhydrazyl (DPPH) with high correlation coefficients (0.85–0.91) and small standard error of cross-validation (RMSECV) ranged from 0.08 to 0.33. The prediction capacity (RPD) for TPC, TFC, TAC, FRAP, and DPPH ranged from 3.30 to 8.25, thus demonstrating that the near infrared spectroscopic (NIRS) equations developed were applicable to unknown samples. This study demonstrates that NIRS can be considered as a fast tool for the nondestructive determination of antioxidant compounds (phenolics and flavonoids) and antioxidant activity of the Hs.     

Antioxidant and anticholinesterase activity of essential oils and ethanol extracts of <Emphasis Type="Italic">Thymus algeriensis</Emphasis> and <Emphasis Type="Italic">Teucrium polium</Emphasis> from Algeria

This study aimed to investigate the cholinesterase (ChE) inhibitory and antioxidant activities of essential oil (EO) and ethanolic extract (EE) of two Lamiaceae medicinal plants from Algeria: Thymus algeriensis Boiss. & Reut. and Teucrieum polium subsp capitatum. The chemical composition of EOs analyzed by GC and GC–MS revealed the presence of carvacrol (43.2%), p-cymene (18.7%) and γ-terpinene (14.8%) as major compounds in T. algeriensis, while germacrene D (25.0%), bicyclogermacrene (10.4%), β-pinene (11.3%) and spathulenol (5.8%) were the most important components in T. polium oil. The best inhibitory activity on acetylcholinesterase (AChE) was exhibited by the EO of T. algeriensis. On the other hand, T. polium oil was more efficient against butyrylcholinesterase (BChE) than against AChE, whereas EEs showed weak or no inhibitory effect, particularly against AChE. Antioxidant activity was evaluated by β-carotene bleaching, ferric and cupric reducing powers and inhibition of ABTS^?+, DPPH^? and superoxide radicals. EOs showed different antioxidant trends depending on the assay used while ethanol extracts had high activity with all tests.     

Effect of Dipping Pre-treatment with Unripe Grape Juice on Dried “Golden Delicious” Apple Slices

The consumption of apple chips is increasing in the last decades because of the consumer’s preferences towards healthy snacks. However, the enzymatic browning, which is attributed mainly to polyphenol oxidase (PPO, EC 1.10.3.1) activity, negatively affects the sensory, nutritional, and antioxidant properties of dried apples as a consequence of the oxidation of phenolic substrates during post-harvest stages. The antibrowning and antioxidant effects of dipping pre-treatments with unripe grape juice as well as reference formulations including a mixture of 1% w/v ascorbic acid and 1% w/v citric acid, 6% w/v NatureSeal®, and 0.1% w/v sodium metabisulfite were evaluated by spectrophotometric and colorimetric assays on dried “Golden Delicious” apple slices. Based on HPLC analysis, the treated apple slices were enriched with bioactive compounds which effectively improved antioxidant capacity and limited enzymatic browning by increasing lightness, reducing color change, and inhibiting PPO activity. Hence, the juice of unripe grapes recovered as agricultural wastes during bunch thinning of vineyards could be proposed as a safe, inexpensive, and eco-friendly alternative to conventional antibrowning treatments in apple processing.     

The Comparison of Cinnamomi Cortex and <Emphasis Type="Italic">Cinnamomum burmannii</Emphasis> Blume Using <Superscript>1</Superscript>H NMR and GC-MS Combined with Multivariate Data Analysis

Cinnamomi Cortex (CC, rougui) is the stripped trunk bark of Cinnamomum cassia Presl (CCP) and commonly is used to treat dyspepsia, gastritis, blood circulation disturbances, and inflammatory diseases. However, Cinnamomum burmannii Blume (CBB), an edible ingredient in food from a different Cinnamomum, sometimes replaces CC due to their similar functions and appearance. To identify and distinguish CC from CBB, we investigated the metabolite differences in polar and non-polar extracts of these species by high-resolution ¹H nuclear magnetic resonance (¹H NMR) spectroscopy and gas chromatography–mass spectrometry (GC-MS) combined with multivariate statistical analyses. The results showed a significantly higher separation in GC-MS analysis (non-polar extracts) than ¹H NMR analysis (polar extracts). One-way ANOVA revealed that polar extracts (acetate, α-glucose, sucrose, glycerol, fructose) and non-polar extracts (trans-cinnamaldehyde, α-copaene, δ-cadinene, 2-methoxycinnamaldehyde, (?)-calamenene, α-muurolene, γ-muurolene, α-calacorene, cubenol and α-muurolol) contributed greatly to the comparison of CC and CBB. These results indicate that the ¹H NMR- and GC-MS-based metabolomic approach can effectively differentiate the phytochemical compositions among different species in plants, which in turn could identify important metabolites with known pharmacological activity.     

Volatile Constituents of Jambolan (<Emphasis Type="Italic">Syzygium cumini</Emphasis> L.) Fruits at Three Maturation Stages and Optimization of HS-SPME GC-MS Method Using a Central Composite Design

The volatile compounds of jambolan (Syzygium cumini L.) fruit were determined at three different maturity stages (unripe, half-ripe, and ripe) by headspace solid-phase microextraction (HS-SPME)–gas chromatography-mass spectrometry (GC-MS) technique using five different fibers (Fused silica PDMS/DVB, DVB/CAR/PDMS, PEG, Stable flex PDMS/DVB, and PDMS). The optimal extraction conditions were evaluated using different variables such as adsorption temperature (minimum 25 °C, maximum 55 °C), salt quantity (minimum 0, maximum 30.0%), and extraction time (min 10, max 30 min). The major classes of compounds identified were ester, terpene, alcohol, aldehyde, and carboxylic acid. Ninety volatile compounds with characteristics aroma attributes were identified, and the primary compounds linked with development of characteristics aroma of ripe jambolan fruit pulp were trans-β-ocimene, β-ocimene, caryophyllene, humulene, D-α-pinene, L-β-pinene, β-pinene, D-limonene, α-terpineol, neo-allo-ocimene, 2-hexenal (E), δ-cadinene, 3-hexen-1-ol, (Z) β-linalool, terpinolene, eremophilene, valencene, 1-hexanol, longipinene, γ-terpinene, γ-muurolene, endo-borneol, o-cymene, nonanal, terpinen-4-ol, β-terpineol, α-muurolene, fenchol, α-fenchene, β-thujene, benzaldehyde, (E)-2-hexenal, β-cadinene, and decanal.