Assessment of Agro-Morphological Variability in a Durum Wheat Collection Maintained in the Moroccan Gene Bank

Durum wheat is one of the most important cereal crops in Morocco. The development of high-yielding varieties of durum wheat is one of the major goals of breeding programs in Morocco. Crop genetic diversity should play an essential role in this context. The objective of this study was to assess the genetic variation among 280 durum wheat accessions conserved at the Moroccan Gene Bank by using twelve agro-morphological characters. All accessions are planted in field conditions and arranged in augmented design. The results showed a large variability among the durum wheat accessions. Analysis of variance demonstrated significant to highly significant differentiation between the accessions for the most traits. The number of plants at the emergence stage, the biomass of the plant at the flowering stage, the chlorophyll content, and the number of spikes showed high genetic advance coupled with high heritability (broad sense). Moreover, highly significant coefficients of correlation were revealed between agro-morphological characters offering the possibility of direct or indirect selection. The first two axes of the principal component analysis explained 45% of the total variation and showed that Moroccan landraces and North American cultivars shared similar morphological characters. However, Moroccan cultivars have shown better agronomic characters. This important agro-morphological variation should be utilized as a gene pool in durum wheat improvement to develop novel varieties with high productivity and the best quality.

Quality of Different Papaya Cultivars Grown in the Greenhouse throughout the Year in Subtropical Regions

Harvest time is one of the factors affecting postharvest fruit quality. Under the subtropical condition, greenhouse cultivation allows a year-round harvest. However, the crop should meet the quality and the marketing criteria for overall customer satisfaction. This study aims to determine the impact of the harvest season on the quality characteristics of papaya fruit. For this purpose, two different cultivars (Sel-42 and Tainung) were grown in the greenhouse and harvested in the winter, the summer, the spring, and the autumn of two years. Sampling was carried out at the same visual maturity stage at each season. The two cultivars had soft fruit flesh almost throughout the year, although the fruit harvested in the winter had a better visual appeal in terms of color. Both fruit cultivars harvested in the autumn had higher soluble solids and lower acidity. The highest concentrations of total phenolic content and L-ascorbic acid were observed in the spring and summer season harvested fruits although there was no significant difference between those (P > 0.05). It was concluded that the growth in the greenhouse minimizes the harvest season effects on papaya fruit quality. Thus, greenhouse cultivation is recommended for a higher quality product, especially in a subtropical climate.

Biofilms from Pathogenic Bacteria in Food Processing Environments: Formation and Preventive Disinfection Procedures

The ability of some pathogenic bacterial species to form biofilms on surfaces of equipment and utensils is of great concern to the food industry since they represent a continuous source of contamination in food processing environments. In this review, the factors involved in the formation of microbial biofilms are highlighted, along with a discussion on the preventive disinfection procedures recommended to avoid the attachment of microbial cells on surfaces of equipment and utensils in food processing areas. Relevant articles published in the last 10 years (2012-present) were selected in PubMed, Science Direct, and Google Scholar. Methods for assessing the adhesion and biofilm formation ability of strains isolated from surfaces in the food industry environment are also presented.

Impact of Encapsulation Wall Materials and Drying Method on Physicochemical Properties and Digestibility of Encapsulated Chayote (Sechium edule (Jacq.) Swartz) and Kohlrabi (Brassica oleracea var gongylodes L.) Extracts

Chayote (Sechium edule (Jacq.) Swartz) and kohlrabi (Brassica oleracea var gongylodes L.) are medicinal plants widely distributed in Thailand. Several traditional medicines usually contain these extracts due to their pharmaceutical activities. However, appropriate technologies that are used for protection, stabilization, and slow release of plant extracts are a lot desired in terms of food application. In this study, chayote and kohlrabi extracts were encapsulated by several kinds of wall materials (maltodextrin, and the combination of maltodextrin and gum arabic or alginate) and drying methods (freeze-drying and tray-drying techniques). Thus, the objective of this research was to determine morphological and physicochemical properties, wall materials releasing, and antioxidant activity of encapsulated chayote and kohlrabi extracts powder. The morphology of all encapsulated chayote and kohlrabi extracts powder showed irregular spherical shape, monodispersity, and smooth surface. The encapsulated chayote and kohlrabi extracts powder with tray-drying technique tend to have more darkness and redness in color than the freeze-drying technique. Wall material releasing was expressed in glucose liberation of encapsulated extracts powder after amylolytic enzyme digestion. Encapsulation using maltodextrin as wall material provided higher wall material releasing than the other samples. After digestion analysis, the digested residues were examined for antioxidant activity. The results showed that the combination of maltodextrin and alginate for both freeze-drying and tray-drying techniques provided higher antioxidant activity after 60 and 120 min of digestion. Thus, the combination of maltodextrin and alginate, and drying with the freeze-drying technique was the best treatment in this experiment. This data can lead to a better understanding of wall materials types and releasing characteristics, which are used to control bioactive compounds liberation in the gastrointestinal tract.

Emitter Clogging and Hydraulic Performance of Drip System under Different Water Qualities and Placement Techniques

The present study was conducted at the Indian Agricultural Research Institute, New Delhi, India, to evaluate the effect of sand-disc filters, pressure compensating (bioline) and non-pressure compensating (inline) emitters, and surface and subsurface placement of laterals on emitter clogging using wastewater and groundwater for irrigation. Results of this study revealed that besides water quality, the type of emitter, placement of laterals, and emitter position on laterals affected emitter's clogging. The major cause of clogging was associated with the precipitated substance accumulated at the emitter inlet concurrently close the micro-pore channels of the emitter, consequently reduce the emitter discharge. The major substances that took part in the clogging of emitter were EC, pH, HCO3, Turbidity, total solid, Escherichia coli (E. coli), and total coliform. It was observed that these substances (HCO3, Turbidity, total solid, E. coli, and total coliform) of groundwater and wastewater were categorized with a medium risk of clogging except for magnesium (low risk of clogging). Pressure compensating drip emitter showed better performance against clogging as compared to non-pressure compensating drip emitter. Sub-surface placement of drip emitter was more prone to clogging under both wastewater and groundwater. It was observed a significant (p ≤ 0.05) effect of lateral placement, emitter types, and the interaction between these factors on emitter's clogging under both types of water. Emitter flow rate decreased with the increasing time of operation of the drip systems at normal operating pressure, because of clogging of emitters. By flushing operation, it was observed a 3 to 5% higher flow rate in inline drip emitter than bioline (1-2%). The R2 value, which precisely describes the head-discharge relationship, was high (0.99) in most of the bioline treatments. This study also observed and recommended that pressure compensating emitter would be the most appropriate technique to reduce the clogging while using wastewater for irrigation. Flushing effectively controlled the emitter's clogging thus improved the emitter's water discharge rate.

Differential Effect of Nobiletin and Tangeretin on the Antioxidant Activity and Levels of α-Tocopherol and Retinol in Rats

Polymethoxylated flavones (PMFs) have been associated with increased antioxidant activity in animal models. The effects of tangeretin (TAN) and nobiletin (NOB) on antioxidant activity in the blood and liver of rats were evaluated. Groups of rats were treated with 200 mg/kg bw/day of TAN or NOB, or placebo, for 15 days. Parental compounds and their metabolites were assessed in the liver by chromatographic analysis, in addition to α-tocopherol and retinol in the blood serum. Both TAN and NOB supplements were able to reduce malonaldehyde (MDA) in the rat’s blood by 22% and 18%, respectively, but only NOB increased redox reaction by 3%. Blood levels of retinol and α-tocopherol increased under TAN by 59% and 20%, respectively, but were not affected by NOB. Eight NOB metabolites were detected in the liver, but only two TAN metabolites were identified in low concentration. In conclusion, NOB improved antioxidant capacity and reduced lipid peroxidation, while increased levels of retinol and α-tocopherol after TAN supplement may have contributed to decreased blood lipid peroxidation.

Human Health Risk Assessment of Some Selected Heavy Metals in Brassica rapa var. parachinensis in Peninsular Malaysia

Biomonitoring of heavy metals is an important part of the ecotoxicological study. However, without the application of the metal data to reflect human wellbeing, it is considered the low impact on the society. In this study, the heavy metals in green mustard Brassica rapa var. parachinensis were collected from Sikamat (Negeri Sembilan in 2013), Kg. Sitiawan (Perak in 2016), and Ara Kuda (Penang in 2016) of Peninsular Malaysia, were determined. The samples are analyzed for the concentrations of Cu, Fe, Ni, Pb, and Zn by using the flame atomic absorption spectrophotometer. For the leafy edible part, the metal concentrations (mg/kg dry weight) ranged from 16.1-18.5 for Cu, 145-207 for Fe, 1.02-1.64 for Ni, 0.90-2.73 for Pb, and 74.0-203 for Zn. These metal data were assessed for human health risks. It was found that all the values of target hazard quotients for Cu, Fe, Ni, Pb, and Zn in both adults and children were less than 1.00. This exhibited there were no non-carcinogenic risks of the five metals through the intake of the Brassica from the present study. This could indicate that the accumulation of metals and pollution threshold is below the limit of causing hazardous effects to consumers. Nonetheless, regular assessment of health risks of heavy metals in this vegetable needs to be conducted from time to time these vegetables are prone to continuous heavy metal contamination.

Quantum Cascade Laser Photoacoustic Spectroscopy Applied to Rice Flour Analysis

In the present work we applied laser photoacoustic spectroscopy (LPAS) to the analysis of food samples. In particular, we analyzed samples of different rice flours (standard and commercial ones). For this purpose, a laboratory system based on quantum cascade laser (QCL) has been developed and characterized. After that, the LPAS spectra of all the rice samples were collected with a standard error of less than 2% of the measured value and a background signal negligible compared to the sample signals. All the experimental LPAS spectra resulted to be rich in spectral features showing clear differences between each other. The experimental spectra were then analyzed by comparison with the FT-IR transition frequency recorded in our laboratory to consent a proper assignment. Finally, to put in evidence the small differences among the various rice types, the Principal Component Analysis (PCA) was applied to the recorded LPAS spectra highlighting five different groups corresponding to the five types of samples. In conclusion, the present work demonstrated the discriminating capability of LPAS technique in the case of different types of rice flour samples.

Agronomic and Morpho-Physiological Characterization of Some Advanced Lines being Selected in Durum Wheat Cultivated in Semi-Arid Conditions

Knowledge of agro-physiological traits associated with drought tolerance would be useful for developing breeding materials for drought-prone environments. This study was conducted to estimate genetic variability among nine durum wheat genotypes in response to drought. Our results indicated that the effect of the campaign, genotype, and genotype × interaction was significant for the thirteen variables measured, except for the relative water content. The variability observed was greater for grain yield, biomass, ear fertility, straw and economic yields, chlorophyll content, and cell integrity. Heritability was high for the number of grains per ear and the chlorophyll content; medium for thousand kernel weights, low for grain yield, biomass, and economic yield, and zero for the rest of the variables measured. The results also showed that the agro-morphological characters were significantly linked to each other, unlike the physiological characters which showed non-significant relation between them and with the agro-morphological characters. This suggests that among the varieties evaluated, the selection of those which are tolerant and with high yield potential should therefore be made on a case-by-case basis and not based on a specific physiological character, a marker of tolerance, highly correlated with yield grain. The nine varieties evaluated were subdivided into three divergent clusters of three varieties each. Cluster C1 consists of the least performing varieties, unlike the other two clusters which bring appreciable gains for several characteristics including grain yield, biomass, the weight of 1000 grains, straw yield, and ear fertility and a marked improvement in chlorophyll content and a significant reduction in damage to the cell membrane by thermal stress. In conclusion and following their divergence, it is suggested to use the varieties of clusters C2 and C3 in crossing with the varieties of cluster C1 to improve and reconcile stress tolerance and yield potential in the same genetic background.

Assessment of Growth and Technological Performances of Yogurt Bacteria Isolated From Local Turkish Yogurts

Growth patterns and some technological performances of five Streptococcus thermophilus and seven Lactobacillus delbrueckii subsp. bulgaricus strains isolated from yogurt samples which were collected from remote rural areas of Anatolia, Turkey were assessed. The single isolates were screened for milk acidification performances, production of volatile organic compounds and texture developing properties, and selected isolates were combined to use in yogurt-making. Yogurt samples were subjected to sensory evaluations as well as fermentation profiles. Finally, the combinations of one Streptococcus thermophilus isolate with all Lactobacillus delbrueckii subsp. bulgaricus strains were found to have potentials for further evaluations regarding their suitability for commercial applications.