Ali Sabir

The fatty acid and tocopherol constituents of the seed oil extracted from 21 grape varieties (Vitis spp.)

BACKGROUND Fatty acids and tocopherols in appropriate quantities are invaluable attributes that are desirable in seeds of agricultural products. Studies have generally focused on the evaluation of the oil and tocopherol components of oil crops. Recently, investigations revealed that the grape seed has robust potential in the production of healthy fatty acids as well as tocopherols. This study was thus conducted to determine the oil and tocopherol components of grape seeds, obtained from various grape cultivars of different species, including two rootstock varieties. RESULTS The grape seed oil concentration of the studied varieties ranged from 7.3 to 22.4%. The determined fatty acid profiles of the genotypes conformed to the pattern described in the literature for grapes. Linoleic acid is the major component comprising 53.6-69.6% of the total, followed by oleic (16.2-31.2%), palmitic (6.9-12.9%) and stearic (1.44-4.69%). The oils of all the seeds analysed showed a preponderance of α-tocopherol (ranging from 260.5 to 153.1 mg kg⁻¹ oil extract). β-Tocopherol, γ-tocopherol and δ-tocopherol were also detected with the general means of 0.98, 22.2 and 0.92 mg kg⁻¹, respectively. Linoleic acid showed a significantly negative correlation with all the fatty acids analysed. The strongest negative correlation existed between linoleic and oleic acids (r = -0.834, P < 0.01). CONCLUSION Present investigations indicated that oil content, fatty acid composition and tocopherol constituents of grape seed show great variation among the genotypes. Markedly higher proportions of linoleic acid with considerable amounts of tocopherols found in the oil samples suggest that grape seed is a good source for culinary, pharmaceutical and cosmetic uses.

Growth and mineral acquisition response of grapevine rootstocks (Vitis spp.) to inoculation with different strains of plant growth‐promoting rhizobacteria (PGPR)

BACKGROUND Effects of the plant growth-promoting rhizobacteria (PGPR) strains Burkholderia gladii BA-7, Bacillus subtilis OSU-142, Bacillus megatorium M-3 and Azospirillum brasilense Sp 245 on vegetative development and mineral uptake of 1103 P and 41 B grapevine rootstocks were investigated. The roots of nursery plants of the grapevine rootstocks were immersed in bacterial solutions and transplanted to a sterilised peat and perlite mixture in 5 L pots. Plants were cultivated in a semi-controlled glasshouse during the vegetation period. RESULTS Vegetative development of grapevine rootstocks was obviously promoted by bacterial inoculation, with the maximum increase induced by Sp 245. Inoculation with Sp 245 also significantly improved the chlorophyll concentrations of the leaves of the two rootstocks. Among the bacteria, OSU-142 also significantly stimulated vegetative development and mineral acquisition of the plants. Nutrient contents of the leaf blades of the plants were generally higher than those of control plants. CONCLUSION Overall investigations revealed that A. brasilense Sp 245 and B. subtilis OSU-142 performed more efficiently than the other strains. Therefore these bacteria seem to have considerable potential in reducing the need for inorganic fertiliser.

Effects of Different Storage Conditions on Rooting and Shooting Performance of Grapevine (Vitis Vinifera L.) Cuttings in Hydroponic Culture System

The shortfall in grapevine planting materials urged the researchers to enhance rapid propagation techniques with successfully storing the propagation materials such as rootstock and scion canes. The present study was conducted to assess the effects of different storage conditions (cold storage room at 1 °C plus 80-90% relative humidity and sand medium in open area) on rooting and shooting performance of cuttings of seven grapevine cultivars. For assessments, a hydroponic culture system was established in which the cuttings were rooted. Investigations on the cuttings prepared from the canes sampled at 6th, 7th and 8th months of the storage times showed that cold storage room significantly maintained the quality of canes with better callusing, rooting and shooting features. Storage at cold room can be recommended for long term storage, while dipping the canes in damp sand medium can be considered for a short time around a few months keeping of grapevine canes. Grapevine cultivars exhibited slight variation in response to both storage duration and storage conditions.

Postharvest Quality Extension of Minimally Processed Table Grapes by Chitosan Coating

ABSTRACT Demand for fresh grapes is increasing globally due to their rich composition in phenolic compounds, which have a strong antioxidant capacity. However, fresh table grapes deteriorate rapidly due to berry water loss and pathogen growth, which make it difficult to preserve without treatment. Chitosan coating, as a healthy, simple and innovative technology against to common SO2 fumigation, was tested at various concentrations (0%, 0.5%, 1.0% and 2.0%) for the effectiveness on postharvest quality extension of detached grapes of ‘Alphonse Lavallée’ cultivar. Chitosan coating at all doses significantly retarded the loss in berry weight, extended the skin rupture force and total phenol content. Visual quality was higher due to coating the berries with chitosan. Chitosan at all concentrations was effective on delaying maturity index (used to express postharvest senescence) and changes in berry colour values such as L*, C and Hue angle. Among the applied doses, 1% chitosan solution can be recommended to apply since higher doses were more effective with similar results on overall quality features of berries. Overall findings demonstrated that chitosan as an edible coating with their unique barrier can be utilized as a natural preservative of detached grapes to extend the postharvest quality up to 28 days.