Browse
Abstract
This paper provides a rapid method coupled with chemometrics to visualise PEL quality of eight regions. The contents of mineral elements, Vitamin C (Vc), and colour parameters were measured using spectrophotometric methods. The volatile substances were determined by electronic nose (E-nose) and headspace solid phase micro-extraction with gas chromatography-mass spectrometry (HS-SPME/GC-MS). Chemometric analyses were employed to visualise the sample distribution according to the geographical origin. The colour parameters, Vc, and mineral contents of PEL from diverse origins were significantly different (P < 0.05). A total of 25 volatile organic compounds (VOCs) were identified from PELs, with the highest percentage of components being ethyl acetate. The combination of HS-SPME/GC-MS and E-nose can properly characterise PEL samples. Therefore, the results of this exploratory work highlight the possibility of discriminating PEL from different regions.
Abstract
Synthesis of nanoparticles can be long and costly processes using physical and chemical methods. Biological synthesis of nanoparticles is known to be cheaper and easier than other methods. In this study, silver nanoparticles (AgNP) were obtained by biological synthesis, also known as green synthesis, using Sorghum bicolor var. technicum (Körn) Stapf ex Holland seed extract, popularly known as sorghum. AgNPs were characterised by SEM, EDS, TEM, FT-IR, and UV-Vis Spectroscopy. SEM images confirmed that the shape of AgNPs was spherical. TEM analysis showed that the average sizes of AgNPs ranged from 51 to 56 nm. EDS analysis confirmed the presence of AgNPs by detecting a silver ion peak at 3 KeV. UV-Vis spectroscopy analyses indicated that the brown-burgundy colour of AgNPs exhibited maximum absorbance at 450 nm. The biological activities of the extract and AgNPs were investigated through antimicrobial, antibiofilm, antioxidant, mutagenic, and DNA cleavage activity analyses. The extract exhibited the highest MIC value against Gram-positive bacterium Bacillus subtilis (0.62 μg mL−1), whereas AgNPs demonstrated the highest antimicrobial activity specifically against Gram-negative bacterium Escherichia coli (0.31 μg mL−1). The antibiofilm results revealed that the extract displayed the highest percentage of biofilm inhibition against B. subtilis, while AgNPs exhibited notable efficacy against both Candida albicans yeast and Pseudomonas aeruginosa bacterium. The antioxidant activities were evaluated using DPPH• and ABTS•+ methods, and it was determined that both samples had high antioxidant activity. Mutagenicity of the extract and AgNPs were evaluated by the Ames/Salmonella test using two strains of Salmonella typhimurium (TA98 and TA100). The mutagenic activity of the extract increased depending on the concentration for both strains, while AgNP did not show mutagenicity at any concentration. The agarose gel electrophoresis method showed that the extract and AgNPs cleaved DNA in the presence of an oxidising agent.
Abstract
In this study, a water-soluble novel polysaccharide called TPS was successfully prepared and isolated from Liubao tea. The optimal extraction conditions resulted in a yield of 10.70% for the crude TPS. The purified TPS exhibited unique physicochemical properties and structural characteristics. It was identified as an acidic polysaccharide with trace binding proteins, with a →4)-α-D-Galp-(1→) residue. The purified TPS had a dense and uneven appearance, potential crystallisation characteristics, and structural stability. Importantly, it demonstrated the ability to inhibit glucose transport in Caco-2 cells by down-regulating the expression of sodium/glucose cotransporter 1 (SGLT1) and glucose transporter 2 (GLUT2), leading to a hypoglycemic effect. These findings highlight the potential of TPS from Liubao tea as a functional food or additive with hypoglycaemic properties.
Abstract
Cultures used in dairy products make it possible to obtain standard industrial products. However, they all provide a uniform taste and aroma. Generally, non-starter lactic acid bacteria (NSLAB) isolated from raw-milk or artisanal cheeses offer varied sensory characteristics when integrated in cheese provided that biosafety criteria are met. Enterococcus faecium HZ was previously isolated from traditional Turkish cheese and determined to have strong antibacterial activity as well as no gelatinase and hemolysis activities. In this study, this strain was used as adjunct culture in white-brined cheese to improve the physicochemical, textural, and aromatic properties, as well as antimicrobial activity. Cheeses with E. faecium HZ had a higher sensory score, which could be due to the aroma-active compounds produced by this strain. The incorporation of E. faecium HZ also improved the microbial quality of cheeses and showed an inhibitory effect via a stable enterocin production on indicator microorganisms.
Abstract
The nutritional and therapeutic benefits of plants are outstanding. Wild mustard (Sinapis arvensis L.) collected from different regions was analysed for its phenolic, flavonoid, protein, and biological activity levels. In this case, the plant ethanol extract was obtained using a soxhlet apparatus. Rel assay kits and the DPPH test were used to assess the plant's antioxidant activity. The agar dilution test was used to determine antimicrobial efficacy. A549 lung cancer cells were used in an MTT assay to measure antiproliferative activity. The Folin−Ciocalteu reagent was used to quantify the total phenolic content of the sample. The amount of flavonoids was determined using an aluminium chloride test. The amount of protein was calculated using the AOAC's standard technique. Based on the research conducted, it was shown that the maximum total antioxidant status (TAS) value for the ethanol extract of wild mustard from various places was 5.232 ± 0.047 mmol L−1. At a concentration of 2 mg mL−1, DPPH activity was measured to be 82.06 ± 1.01. The maximum levels of total phenolic, flavonoid, and protein were 80.57 ± 2.19 mg g−1, 154.07 ± 2.79 mg g−1, and 7.75 ± 0.24%, respectively. Doses of 25–100 μg mL−1 of plant extracts were effective against fungal strains, whereas doses of 50–200 μg mL−1 were beneficial against bacterial strains. The plant extracts were shown to have potent antiproliferative properties. It was found that wild mustard's phenolic, flavonoid, protein, and biological activity levels varied according to the location from which it was gathered. It was also concluded that wild mustard had significant biological activity.
Abstract
The aim of this study was to assess the nutritional quality of homemade beef sausages by examining the amino acid, biogenic amine, and fatty acid composition. The most abundant amino acids were Ala (15.56%), Leu (13.28%), Gly (8.64%), Pro (8.41%), Ser (8.26%), and Val (7.65%). The essential amino acids accounted for 44.30% of total amino acids. Apart from the protein building amino acids, the free amino acid content was relatively high, accounting for 10% of total amino acid content. The average biogenic amine concentration in the sausage samples was low (1.69 mg kg−1). Saturated fatty acids accounted for 59.10% of total fatty acids, followed by monounsaturated (38.63%) and polyunsaturated fatty acids (2.27%). The fatty acid profile was dominated by oleic (C18:1, 34.37%) and palmitic (C16:0, 30.24%) acids, and short-chain fatty acids were also present, which may have a positive impact on gut health. The results show that beef sausages have a high nutritional value and are a good source of essential amino acids, free amino acids, and fatty acids that are important for human health.
Abstract
In this study, it is aimed to encapsulate some functional components of the olive leaves. Olive leaf extract was encapsulated using solution of sodium alginate, sodium alginate/gelatine, and sodium alginate/agar as wall material by ionic gelation technique. Also, olive leaf extract was encapsulated using solution of gelatine as wall material by cold gelation technique. The viscosities of the coating materials used in the study were investigated. An optimisation process was carried out to determine the injection time to be applied in the ionic gelation technique and the encapsulation efficiencies, particle sizes, swelling ratios, in vitro release profiles, and antioxidant activities of the obtained capsules were determined. While the encapsulation efficiency of the capsules obtained by the cold gelation technique was determined as the highest (98.2 ± 0.99%), it was revealed that the viscosity of the wall material used in the ionic gelation technique was important in the encapsulation efficiency. The particle size and swelling rate of the capsules obtained using the cold gelation technique were the highest. The release rate of oleuropein was generally higher at gastric pH than at intestinal pH. A correlation was found between antioxidant activities and the encapsulation efficiency of capsules.
Abstract
A large amount of waste, especially the outer part of citrus fruits (peel), is generated after consuming the pulp and it remains unused. The valorisation of this waste by recovering its bioactive compounds seems interesting. The aim of this study was to find the optimal conditions using ultrasound-assisted extraction (UAE) that yield the highest carotenoid content and better antioxidant activity from Citrus reticulata Blanco peels.
Response surface methodology (RSM) through Box–Behnken experimental design was used to optimise the conditions for carotenoid extraction using UAE. Hexane concentration, temperature, and sonication time were selected as the main factors.
The results revealed that all independent variables affected the responses. The optimal UAE conditions for hexane concentration, temperature, and sonication time were 60.76%, 36.45 °C, and 37.32 min, respectively. The values of total carotenoid content (TCC) and total antioxidant activity (TAA) obtained by UAE were higher than those obtained by the maceration extraction method.
It can be concluded that the medium and extraction parameters, including hexane concentration, temperature, and sonication time, significantly influenced the recovery of carotenoids and antioxidant activity. The optimisation study allowed determining the appropriate conditions to maximise both responses. Compared to conventional maceration, the UAE method was superior and more efficient for extracting carotenoids from C. reticulata Blanco peels.
Abstract
Food allergies became a major public health and food safety interest in the past decades as their prevalence is increasing, and their only available treatment is a strict elimination diet that necessitates appropriate food labelling regulations. While such regulations are available worldwide, most of them are not taking into account inadvertent allergen cross-contamination and they usually do not define threshold doses that could support the industry in their endeavour to provide reliable food labels for allergic consumers. This resulted in the proliferation of the “may contain” type precautionary allergen labelling (PAL), which is voluntary and is intended to warn consumers for potential unintended contamination with an otherwise undeclared allergen. As this kind of labelling is hardly ever based on actual risk assessment, it puts both the industry and the consumer into a difficult position. A promising tool towards the solution of this problem could be allergen threshold doses based on clinical data, which are becoming increasingly available. This review intends to present this process, the new ways of improved risk assessment it opens, and its implications for food analysis.
Abstract
The aim of this study was to evaluate the possibility of storage of mangoes (Mangifera indica L.) coated with chitosan-based nano-silver films. Chitosan-based nano-silver films were first made using chitosan with three degrees of deacetylation of 70, 80, and 90%. The films were then used for coating the mango fruits. All coated mangoes and the control samples were stored at 12 °C in a cooling room. The respiration rate, ethylene production rate, weight loss, firmness, total soluble solids, total acid, vitamin C, total sugar, and change of peel colour were evaluated once every 5 days during the storage period. As observed, the coating using the chitosan-based nano-silver films did not induce significant negative alterations on most of the physical characteristics and chemical constituents of the fruits. In addition, the coating using those materials helped reduce the respiration and the ethylene gas production and retard the ripening process of mango fruits. The chitosan-based films with higher deacetylation degrees (CN80 and CN90) better moderated the respiration of mangoes. The coating using chitosan-based nano-silver films prolonged the shelf-life of mangoes (up to 35 days) compared to the control (less than 10 days).
