Development of a GC-MS method and analysis of phenolic acids in fruit and spice matrices and evaluation of their antioxidant capacity

The aim of the present study was to develop a specific and quantitative assay to determine the individual concentrations of naturally occurring phenolic acids and their metabolites in food; then evaluate the antioxidant capacity of the quantified phenolic acids using different assays. A GC/MS method was developed for the quantification of ten commonly present phenolic acids in plant foods. Target analytes were the benzoic acid based phenolic acids - anisic, gallic, p-hydroxy benzoic, o-salicylic, protocatechuic, and vanillic acids, together with the cinnamic acid based phenolic acids - caffeic, p-coumaric, ferulic and sinapinic acids. Deuterated Anisic D7 acid was used as an internal standard to achieve accurate and reliable quantification. Purification was accomplished using C18 solid phase extraction cartridges (ENVI Chrome P, Supelco); sample extracts were derivatized prior to GC-MS analysis using BSTFA and pyridine (4:1 V/V). Resolution and quantification of all compounds were excellent with linear calibration curves over a wide range (0-500 ng/ml) and correlation coefficient (R2) of 0.999. Relative standard deviation (RSD) and response factors (RF) were satisfactory (≥1.1 and >3 respectively) and within the acceptable limits of bioanalytical method validation. The adapted method was applied to different varieties of fresh and sundried Saudi Arabian dates as well as Achacha fruit and eleven selected spices. The results revealed that phenolic acids are present in plant foods mostly in bound form as esters or glycosides. The lipophilic and hydrophilic antioxidant activities of all selected samples were examined using the ORAC assay. In addition, the antioxidant capacity of the identified free and bound phenolic acids was measured by different assays including ORAC, ABTS, DPPH and FCR. The results indicate that hydrophilic antioxidants are higher than lipophilic antioxidants in plant foods and the high phenolic acids content was not correlated with high antioxidant activity. Moreover different antioxidant capacity assays showed different results on the same phenolic acid extracts from different samples (P-value> 0.05). In conclusion the method presented is robust, safe, sensitive and generally applicable to the analysis of free and bound phenolic acids in food samples. The data obtained is sufficiently reliable to be included in food composition databases

Effect of Coatings Using Titanium Dioxide Nanoparticles and Chitosan Films on Oxidation during Storage on White Button Mushroom

White button mushroom or (Agaricus bisporus) is known as a healthy foodstuff with several nutrients, polyphenols, proteins, and dietary fibers. Mushrooms have a short shelf-life, approximately three to four days at commercial storage and about eight days under chilling conditions. In the current study, titanium dioxide nanoparticles and chitosan films were used as novel active coating materials with the addition of thymol and tween (T and T) as food preservatives to prolong mushroom shelf life up to 12 days. Chitosan, Chitosan-Nano, and Chitosan-Nano/TT were used as coating materials, while water was used as control. Chitosan-Nano/TT film reported the lowest peroxidase activity (0.005 U kg−1 FW) and the highest superoxide dismutase activity (4.033 U kg−1 FW), while catalase activity in Chitosan-Nano film was (0.45 U kg−1 FW). Chitosan-Nano film enhanced the reactive oxygen species production levels, DPPH radicals (74.70%), and malondialdehyde content (1.68 µmol kg−1FW). Chitosan-Nano/TT film preserved the respiration rates (O2 consumption −0.026 mmol s−1kg−1, CO2 production −0.004 mg CO2 kg−1s−1) and increased the phenolic contents (0.38 g kg−1). The results suggested that nano-coating films can increase the oxidation processes which enhanced the quality of the mushrooms

Chitosan, Nisin, Silicon Dioxide Nanoparticles Coating Films Effects on Blueberry (Vaccinium myrtillus) Quality

Chitosan coating plus silicon dioxide nanoparticles and nisin were applied on fresh blueberry samples in order to find out safety packaging assay during the post-harvest process. Studies were performed in-vitro for fruit quality as physicochemical parameters and oxidation, while microbiological analyses as molds/yeast and mesophilics populations were examined in-vivo. The selected silicon dioxide nanoparticles 1% and nisin 1%, were added into a chitosan solution, which resulted in four groups of coated blueberries. After storage at ambient temperature, fruits were examined for two, four, six, and eight days. It was noticed that the hardness, chewiness, and cohesiveness of all blueberry samples were increased during the storage. Chitosan-nano-silicon dioxide (CHN-Nano) and (CHN-N-Nano) with the addition of nisin helped to control shrinking (38.52%) and decay rates (8.61%). Moreover, (CHN-N-Nano) reported the lowest L* values (10.54) for the color index, and inhibited the microbial populations (3.60 and 2.73 log CFU/g) for molds/yeast and mesophilics, respectively. (CHN-Nano) reported the lowest value for ph (2.61) and the highest for anthocyanin content (75.19 cyanidin-3-glucoside mg/100 g). The chitosan coating substantially maintained Vitamin C (7.34 mg/100 g) and polyphenoloxidase (PPO) (558.03 U min−1·g−1). The results suggest that nano-material with chitosan film coatings that contained nisin were effective for fresh blueberry preservation under ambient temperature

Boosting of Antioxidants and Alkaloids in Catharanthus roseus Suspension Cultures Using Silver Nanoparticles with Expression of CrMPK3 and STR Genes

Global agricultural systems are under unprecedented pressures due to climate change. Advanced nano-engineering can help increase crop yields while ensuring sustainability. Nanotechnology improves agricultural productivity by boosting input efficiency and reducing waste. Alkaloids as one of the numerous secondary metabolites that serve variety of cellular functions essential for physiological processes. This study tests the competence of silver nanoparticles (AgNPs) in boosting alkaloids accumulation in Catharanthus roseus suspension cultures in relation to the expression of C. roseus Mitogen Activated Protein Kinase 3 (CrMPK3) and Strictosidine Synthase (STR) genes. Five concentrations (5, 10, 15, 20 and 25 mg·L−1) of AgNPs were utilized in addition to deionized water as control. Results reflected binary positive correlations among AgNPs concentration, oxidative stress indicated with increase in hydrogen peroxide and malondialdehyde contents, activities of ascorbate peroxidase and superoxide dismutase, expression of the regulatory gene CrMPK3 and the alkaloid biosynthetic gene STR as well as alkaloids accumulation. These correlations add to the growing evidence that AgNPs can trigger the accumulation of alkaloids in plant cells through a signaling pathway that involves hydrogen peroxide and MAPKs, leading to up-regulation of the biosynthetic genes, including STR gene

Bioactives of Pomegranate By-Products and Barley Malt Grass Engage in Cereal Composite Bar to Achieve Antimycotic and Anti-Aflatoxigenic Attributes

Food is the source from where a person obtains the body’s daily requirements. People’s current daily habits force them to consume fast food, which is known for its poor nutritional and safety features. So, it is urgent to provide a suitable substitution product to solve this issue. The present investigation aimed to produce a bar with a dual function: nutritional and long shelf life. Two materials were chosen to support the bar manufacturing regarding their bioactive contents, barley malt grass (BMG) and pomegranate byproducts (PBD). Chemical composition, antioxidant, and antimicrobial potency were measured. Β-carotene, vitamin C, and tocopherol were determined using HPLC apparatus. Extracts’ bio-safety against cell lines was determined, besides their enhancement against cell-death factors. Simulation experiments were designed to evaluate extracts’ impact to extend bar shelf life. Data represented the richness of essential minerals and fibers. Results of the FTIR reflected the existence of various active groups in the contents. Phenolic fractions of PBD are distinctive for their content of ellagic (39.21 ± 5.42 mg/kg), ferulic acid fractions (31.28 ± 4.07 mg/kg) which is a known with antifungal activity. Extracts and their mix (1:1) represented inhibition zone diameters that reach 15.1 ± 1.66 mm for bacteria and 23.81 ± 1.41 mm for fungi. Extracts were shown to have better safety against the cell line strain of hepatic HL-7702, with an elevation of a harmful dose of aflatoxin (IC50 304.5 µg/mL for PBD, IC50 381 µg/mL for BMG). Sensory evaluation of fortified bars reflected a preferable application of mix (1:1) due to color attributes and panelist evaluations, the same result recorded for simulation studies. The experiment recommended applying a mix (1:1) of BMG: PBD in addition to their extracts (200 mg/kg dough) for functional bar manufacturing with antifungal properties

The In Vitro Analysis of Postbiotics in Functional Labneh to Be Used as Powerful Tool to Improve Cell Surfaces Properties and Adherence Potential of Probiotic Strains

Postbiotics are functional bioactive substances manufactured during fermentation in a food matrix, which can be used to improve human health, but their influence on the adhesion potential and physicochemical cell surface of probiotics is still unclear. We examined the postbiotic influence produced by Escherichia coli Nissle 1917 in functional labneh on cell surface properties (auto-aggregation, hydrophobicity, and co-aggregation) and the adhesion capacities of three probiotic strains. The most commonly detected effects of probiotics, particularly Lsyn−7, were an increase in auto-aggregation, hydrophobicity, co-aggregation, and adhesion ability of the tested strains. Lactobacillus rhamnosus with Lsyn−7 (59%) presented the highest hydrophobicity, whereas the least adhesion to xylene was detected in L. rhamnosus with LHM. Lactobacillus casei with Lsyn−7 showed the highest auto-aggregation after 24 h (60.55%). Moreover, it also has a strong adhesion to Caco-2 cells and effectively prevents the binding of Salmonella Typhimurium to Caco-2 cells. Lactobacillus plantarum with Lsyn−7 presented the strongest co-aggregation with Staphylococcus aureus (85.1%), S. typhimurium (85. 02%) and Listeria monocytogenes (77.4%). The adherence potential of tested probiotic strains was highly correlated with auto-aggregation, hydrophobicity, co-aggregation, and competitive inhibition of L. monocytogenes and S. typhimurium. The findings suggest that Lsyn−7 can be a candidate to promote the adhesion potential of selected probiotic strains. For the reason that the application of probiotic strains has been more interested in their positive influences in the gastrointestinal tract, it is essential to use some functional compounds, such as postbiotics, to improve adhesion abilities and cell surface properties in terms of bacterial binding

Optimization of the Frying Temperature and Time for Preparation of Healthy Falafel Using Air Frying Technology

Air-frying is an innovative technique for food frying that uses hot air circulation to prepare healthy products. The objectives of this study were to establish simplified models to reflect the efficacy of the air frying process at varying temperatures and times on the quality attributes of falafel, and to optimize the frying conditions for producing air-fried falafel. Moisture content, color, fat content, hardness, and sensory evaluation of the fried falafel were analyzed under varied temperatures (140 °C, 170 °C, and 200 °C) and time periods (5 min, 10 min, and 15 min). Statistical analysis was then applied to obtain the best fit model that can describe the properties of fried falafel. Results indicated that moisture content, fat content, and L*-value of air-fried falafel were adversely related to the frying temperature and time, but the hardness and ΔE of fried falafel were increased as the frying temperature and time increased. Moreover, an increase followed by a decrease was shown for the appearance, aroma, crispness, taste, and overall preference scores with the increase in frying temperature and time. The regression analysis showed that the proposed models could be properly used for predicting the properties of the fried falafel. In addition, the overlaid plots resulted in the optimum frying temperature of 178.8 °C and time of 11.1 min. Interestingly, the fat content of the air-fried falafel reduced by 45% at optimal frying conditions compared with that for the deep-fat fried one at 180 °C for 7 min (control). In comparison, the air-fried falafel was lower in fat content, higher in hardness with more acceptable appearance and crispness scores than deep-fat fried falafel. Such information could be beneficial to the manufacturers of the falafel to produce an optimal and healthy product

Investigating the Nano-Films Effect on Physical, Mechanical Properties, Chemical Changes, and Microbial Load Contamination of White Button Mushrooms during Storage

Nutrient-rich edible white button mushrooms were coated with Chitosan (1%), Chitosan/nano-silica, and Chitosan/nano-titanium and then stored at 4 °C to investigate the physical, mechanical properties, chemical changes, and microbial load contamination at an interval of 3 days up to a 12 days storage period. It was noticed that Chitosan/nano-titanium and Chitosan/nano-silica preserved the weight loss percentages as 11.80% and 12.69%, respectively. Treatment with Chitosan/nano-silica coating was found to have positive impacts on the overall color parameters. Both of the nano-coating films enhanced headspace gas compositions and firmness. Chitosan/nano-silica samples recorded the least electrolyte leakage value (24.44%), as low oxygen gas concentration can reduce the respiration rate, weight loss, and cap opening. Chitosan/nano-titanium treatment showed the lowest cap opening value (19.58%), PPO activity (16.98 mg−1 protein), and microbial load contamination (6.12 log CFU/g) at the end of the whole storage period, suggesting that nano-films are a promising preservation method for prolonging the white button mushroom’s shelf-life

Biochar and Chitosan Regulate Antioxidant Defense and Methylglyoxal Detoxification Systems and Enhance Salt Tolerance in Jute (<i>Corchorus olitorius</i> L.)

We investigated the role of biochar and chitosan in mitigating salt stress in jute (Corchorus olitorius L. cv. O-9897) by exposing twenty-day-old seedlings to three doses of salt (50, 100, and 150 mM NaCl). Biochar was pre-mixed with the soil at 2.0 g kg−1 soil, and chitosan-100 was applied through irrigation at 100 mg L−1. Exposure to salt stress notably increased lipid peroxidation, hydrogen peroxide content, superoxide radical levels, electrolyte leakage, lipoxygenase activity, and methylglyoxal content, indicating oxidative damage in the jute plants. Consequently, the salt-stressed plants showed reduced growth, biomass accumulation, and disrupted water balance. A profound increase in proline content was observed in response to salt stress. Biochar and chitosan supplementation significantly mitigated the deleterious effects of salt stress in jute by stimulating both non-enzymatic (e.g., ascorbate and glutathione) and enzymatic (e.g., ascorbate peroxidase, dehydroascorbate reductase, monodehydroascorbate reductase, glutathione reductase superoxide dismutase, catalase, peroxidase, glutathione S-transferase, glutathione peroxidase) antioxidant systems and enhancing glyoxalase enzyme activities (glyoxalase I and glyoxalase II) to ameliorate reactive oxygen species damage and methylglyoxal toxicity, respectively. Biochar and chitosan supplementation increased oxidative stress tolerance and improved the growth and physiology of salt-affected jute plants, while also significantly reducing Na+ accumulation and ionic toxicity and decreasing the Na+/K+ ratio. These findings support a protective role of biochar and chitosan against salt-induced damage in jute plants