Molecular Characterisation of Aflatoxigenic and Non-Aflatoxigenic Strains of Aspergillus Section Flavi Isolated from Imported Peanuts along the Supply Chain in Malaysia.
Peanuts are widely consumed in many local dishes in Southeast Asian countries, especially in Malaysia which is one of the major peanut-importing countries in this region. Therefore, Aspergillus spp. and aflatoxin contamination in peanuts during storage are becoming major concerns due to the tropical weather in this region that favours the growth of aflatoxigenic fungi. The present study thus aimed to molecularly identify and characterise the Aspergillus section Flavi isolated from imported peanuts in Malaysia. The internal transcribed spacer (ITS) and β-tubulin sequences were used to confirm the species and determine the phylogenetic relationship among the isolates, while aflatoxin biosynthesis genes (aflR, aflP (omtA), aflD (nor-1), aflM (ver-1), and pksA) were targeted in a multiplex PCR to determine the toxigenic potential. A total of 76 and one isolates were confirmed as A. flavus and A. tamarii, respectively. The Maximum Likelihood (ML) phylogenetic tree resolved the species into two different clades in which all A. flavus (both aflatoxigenic and non-aflatoxigenic) were grouped in the same clade and A. tamarii was grouped in a different clade. The aflatoxin biosynthesis genes were detected in all aflatoxigenic A. flavus while the non-aflatoxigenic A. flavus failed to amplify at least one of the genes. The results indicated that both aflatoxigenic and non-aflatoxigenic A. flavus could survive in imported peanuts and, thus, appropriate storage conditions preferably with low temperature should be considered to avoid the re-emergence of aflatoxigenic A. flavus and the subsequent aflatoxin production in peanuts during storage.
Marker-assisted backcrossing to improve seed oleic acid content in four elite and popular peanut (Arachis hypogaea L.) cultivars with high oil content.
High oleic acid composition is an important determinant of seed quality in peanut (Arachis hypogaea) in regard to its nutritional benefits for human health and prolonged shelf-life for peanut products. To improve the oleic acid content of popular peanut cultivars in China, four peanut cultivars of different market types were hybridized with high-oleic-acid donors and backcrossed for four generations as recurrent parents using fad2 marker-assisted backcross selection. Seed quality traits in advanced generations derived by selfing were assessed using near-infrared reflectance spectroscopy for detection of oleic acid and Kompetitive allele-specific PCR (KASP) screening of fad2 mutant markers. Twenty-four high-oleic-acid lines of BC4F4 and BC4F5 populations, with morphological features and agronomic traits similar to those of the recurrent parents, were obtained within 5 years. The genetic backgrounds of BC4F5 lines were estimated using the KASP assay, which revealed the genetic background recovery rate was 79.49%-92.31%. The superior lines raised are undergoing a multi-location test for cultivar registration and release. To our knowledge, this is the first application of single nucleotide polymorphism markers based on the high-throughput and cost-effective KASP assay for detection of fad2 mutations and genetic background evaluation in a peanut breeding program.
Antibacterial and anti-biofilm activities of walnut pellicle extract (Juglans regia L.) against coagulase-negative staphylococci.
Juglans regia L. (common walnut) is a deciduous tree belonging to Juglandaceae family. Since ancient time, walnut was widely used in traditional medicine for its antioxidant, antidiabetic, antimicrobial, anti-inflammatory, anti-atherogenic and liver-protective effects. In this work, the antibacterial and anti-biofilm activities of walnuts pellicle extract against coagulase-negative staphylococci were evaluated. Qualitative chemical analysis was performed by the thin layer chromatography. UPLC-Ms/Ms was used to identify the chemical composition of J. regia extract. The total flavonoid and phenolic contents were determined by the Aluminium chloride and Folin-Ciocalteu methods, respectively. The extract showed antibacterial activity with MIC ranging from 3.60 to 461.75 µg/ml and MBC ranging from 461.75 to >461.75 µg/ml. Furthermore, it significantly reduced biofilm biomass and cell viability in a dose-dependent manner. Biological activities of J. regia extract may be due to its high flavonoid and phenolic contents. The obtained results are promising and they deserve further scientific investigations.
A Comprehensive Review on the Chemical Constituents and Functional Uses of Walnut (Juglans spp.) Husk.
The walnut (Juglans spp.) is an appreciated nut that belongs to the Juglandaceae family. The fruit includes four main parts: the kernel, the skin, the shell, and the green husk. It is widely cultivated due to its edible kernel. In walnut production centers, high amounts of the husk as an agro-forest waste product are produced and discarded away. Recently, it has been demonstrated that the walnut green husk could be valued as a source of different natural bioactive compounds with excellent antioxidant and antimicrobial properties. Regarding this respect, in this contribution, the current scientific knowledge on the antioxidant and antiradical activities, various identified and isolated individual chemical constituents, as well as the functional applications of the walnut husk with more emphasis on the Persian walnut (Juglans regia L.) are reviewed.
Impact of the Degree of Maturity of Walnuts (Juglans regia L.) and Their Variety on the Antioxidant Potential and the Content of Tocopherols and Polyphenols.
The aim of the study was to characterize the antioxidant properties; establish the profile of polyphenolic compounds and evaluate the content of tocopherols in walnuts of three varieties (Leopold; Apollo; Resovia) differing in the degree of maturity (harvest date). The profile of polyphenolic compounds was established by UPLC-PDA-ESI-MS. The content of tocopherols was determined by HPLC-FLD. It was found that the content of dry matter and fat increased and the antioxidant properties decreased with the maturation of nuts. Walnuts of the Leopold cultivar harvested in July exhibited the highest content of total polyphenol (2149.08 mg/100 g dry mass). In their polyphenolic profile; 26 compounds were identified; mainly belonging to the class of ellagitannins. The polyphenolic content decreased with the maturation of nuts. The total content of tocopherols in the tested nuts increased with ripening and ranged from 1.76 mg/100g (Apollo VII) to 18.30 mg/100g (Resovia IX).
Synbiotic yoghurt with walnut and cereal brittle added as a next‐generation bioactive compound: Development and characteristics.
The article presents a technology developed for the production of synbiotic Yoghurt with new bioactive filler based on natural components. The Yoghurt has prebiotic and sorption properties. A higher consumer appeal of the product developed has been substantiated; its characteristics compared with the Yoghurt of traditional production technology have been presented. The brittle, containing peeled walnuts, as well as barley, wheat, rye, oatmeal and buckwheat flakes, sugar, and water, was used as a filler. Optimum time and temperature regimes of boiling caramel mixtures and brewing raw walnut-cereal mass in the brittle have been selected. The formulation developed enables increasing the nutritional and biological values of the finished product. The research studies of the finished product involved an analysis of organoleptic, physicochemical, and microbiological points. When performing the tasks, the approved regulatory and technical documentation (GOST) was applied. Each measurement was carried out in triplicate. The physicochemical characteristics of the samples developed were compared with the requirements for the quality of fermented milk products. The nutritional and biological values were calculated. The increase in consumer properties, and nutritional and biological values of the finished dairy product was scientifically substantiated and experimentally confirmed.
Comparative study on the use of three different near infrared spectroscopy recording methodologies for varietal discrimination of walnuts.
Walnut fruit (Juglans regia L.) is an internationally well-known product with an important tradition of consumption. Its health benefits and economic importance in the food industry make this nut an interesting research topic. In this feasibility study, 200 walnut samples of 5 different varieties were collected and their near infrared (NIR) spectra were recorded with 3 different devices: a benchtop Fourier transform near infrared (FT-NIR) spectrograph, a dispersive hyperspectral imaging camera and a portable NIR dispersive spectrograph. Discriminant analyses were applied and different methods for the varietal discrimination of walnuts were obtained and compared. Up to 96 and 84% of correct identification were respectively obtained in internal (training set) and external validations. Better results were obtained covering the entire shell surface than collecting a unique random spectrum per sample. Moreover, FT-NIR and hyperspectral tools produced classification models with a lower classification error in internal and external validations than the portable NIR one.
Characterization and Phytotoxicity Assessment of Essential Oils from Plant Byproducts.
The present work describes the chemical characterization and the phytotoxicity assessment of essential oils (EOs) obtained from spent materials or pruning waste of four plant species: Zingiber officinale Roscoe used in the juicing industry, Pistacia vera L. var. Bronte used in the food industry, discarded material of industrial hemp (Cannabis sativa L. var. Futura 75), and pruning waste from Cupressus sempervirens L. The phytochemical profile of the EOs was evaluated by gas chromatographic flame ionization detection (GC-FID) and GC-MS analyses, which highlighted the presence of several compounds with a wide range of biological activities. Among them, application possibilities in agriculture were evaluated by studying the phytotoxic activity in vitro against germination and initial radical growth of several seeds such as Raphanus sativus L., Lepidium sativum L., Lactuca sativa L., Solanum lycopersicum L., Lolium multiflorum Lam., and Portulaca oleracea L.
Untargeted metabolomics with multivariate analysis to discriminate hazelnut (Corylus avellana L.) cultivars and their geographical origin.
BACKGROUND: In the present study, a metabolomic-based approach was used to discriminate different hazelnut cultivars as well as to trace their geographical origin. On this basis, ultra-high-pressure liquid chromatography coupled to quadrupole-time-of-flight mass spectrometry (UHPLC-ESI/QTOF-MS), able to profile phenolic and sterolic compounds, was set up. RESULTS: Compounds identification was achieved thanks to accurate monoisotopic mass and isotopic pattern, against an in-house database. The screening approach was designed to discern 15 hazelnut cultivars and to discriminate the geographical origin of 6 cultivars originating from the four main growing regions (namely Chile, Georgia, Italy and Turkey). This approach allowed annotating more than 1000 compounds among polyphenols and sterols. The metabolomics data were elaborated with both unsupervised (hierarchical clustering) and supervised (Orthogonal Projections to Latent Structures Discriminant Analysis, OPLS-DA) statistics. These multivariate statistical tools allowed to discriminate hazelnut samples considering both 'cultivar-type' and 'geographical origin'. In particular, flavonoids (anthocyanins, flavanols and flavonols - VIP scores 1.34-1.49), phenolic acids (mainly hydroxycinnamics - VIP scores 1.35-1.55) together with cholesterol, ergosterol and stigmasterol derivatives (VIP scores 1.34-1.49) were the best markers to discriminate samples according to the geographical origin. CONCLUSIONS: This work outlines the potential of untargeted profiling of phenolics and sterols based on UHPLC-ESI/QTOF mass spectrometry to discriminate hazelnut and support authenticity and origin.
Application of multivariate optimization for the selective extraction of phenolic compounds in cashew nuts (Anacardium occidentale L.).
An extraction method based on a multivariate analytical approach was developed for enhancement of the phenolic compounds in cashew nut extracts. The different extractor solvents (acetone, water, ethanol, and methanol) and their binary, ternary, and quaternary combinations were evaluated using a simplex-centroid design and surface response methodology. The special cubic model exhibits no lack of fit and explains 89.2% of the variance. The total phenolic measurements by the Folin-Ciocalteu method revealed the highest values for ethanol (5.93 mg GAE g-1) and acetone-methanol-ethanol ternary mixture (5.92 mg GAE g-1) extracts. ESI (-)-Q/TOFMS analyses combined with PCA and HCA revealed the presence of fatty acids, phospholipids, and sugars in the ternary mixture cashew extract, while for the ethanol extract only phenolic compounds, such as anacardic acids and derivatives, were found. The proposed approach was adequate to reach the optimal extractor which ethanol, a low-toxicity solvent, enabled the selective extraction of a high content of phenolic compounds from cashew nuts.