Improvement of the Raisins Quality Using Plant Growth Regulators

In order to improve the quantity and quality of raisins made from Sultani seedless grapes using plant growth regulators, an experiment was conducted in a randomized complete block design in a commercial vineyard near Bonab city (West Azarbaijan Province, Iran). For this purpose, spraying was carried out at fruit set stage using a combination of CPPU and GA3. Then the produced fruits were turned to raisin using alkaline solutions (Tizabi method) and all assessments in this study were performed on these raisins. It was found that the growth regulator treatments significantly increased the diameter, mass, volume, surface area and wrinkling of raisin, however, these treatments did not affect dry matter and moisture content of the raisins. Significant color changes were observed in all treated raisins and color values of the treated raisins ​​were significantly lower than the control. The interacting effect of the two plant growth regulators was found to be significant for raisins length and total soluble solids, i.e. application of 7.5 mg L-1 of CPPU and 20 mg L-1 GA3 led to the smallest value for the total soluble solids. All treatments increased the raisins length. It could be concluded that application of CPPU and GA3 on grapes results in improvement of the quality of the raisins

Effect of salicylic acid foliar application on Vitis vinifera L. cv. 'Sultana’ under salinity stress

The current survey aimed to study the effect of exogenous salicylic acid (SA) application on salinity stress of grapevine cv. ’Sultana’. The leaves of hydroponically cultivated grapes that were under 0, 75 and 150 mM salinity conditions treated with 0, 0.5, 1 and 1.5 mM SA and after two weeks, the factors such as Na+, K+, proline and MDA contents, leaf electrolyte leakage and enzymatic activities were measured. The results showed that all SA treatments were significantly effective at tolerance enhancement by reduction in Na+/K+ ratio, leaf electrolyte leakage, MDA and H2O2 values and promotion in proline content and the enzymatic activities (POD, APX, CAT and SOD) of grapes. These results indicated that SA application at salinity condition could be applied as a promising method for increasing the salinity tolerance of ‘Sultana’ grapes

Citrus juices technology

Citrus fruits are widely grown throughout the world and contain various bioactive compounds with antioxidant activities including vitamin C, carotenoids, and phenolic compounds. These components are very important for human health and provide protection against harmful free radicals. Citrus fruits are mostly consumed as fresh fruits or fruit juices. To obtain high quality and safe citrus juice, certain critical points (oil extraction from peel, juice extraction, pulp removing, pasteurization, evaporation, and aseptic filling) need to be taken into consideration during citrus juice processing. Firstly, oil extraction from the peel is a necessary step to limit the level of peel oil components in the juice. Secondly, selected juice extraction techniques and process conditions are very important for the yield and total quality of the juice. Thirdly, the pulp removal is an important step to remove most of pectinmethylesterase (PME) and its heat resistance isoenzymes. Further inactivation of remaining PME enzymes and pathogenic or spoilage microorganisms is also obtained with the pasteurization step. Finally, equipment used for the juice production and the concentration conditions have various effects on the sensory properties of the citrus juices. As a result, minimal processing would be applied to citrus juices if the processing steps detailed above are optimized. Obtaining clarified citrus juices from the citruses which have lower carotenoid content including lemon and lime juice is a new trend these days. It is needed to be focused on enzymation (depectinization), clarification assistance agents, and filtration conditions during the clarified juices production. Citrus peel (flavedo) and layer of albedo are the main byproducts of the citrus juice industry. Citrus peel oil is obtained from flavedo layer which has a significant commercial value. Recently, promising nonthermal food preservation technologies were developed including pulsed electric fields (PEF), high pressure processing (HPP), and ultrasonication process (US). These technologies are highly appreciated for their ability to extend the shelf life of food products without the application of heat, thus also preserving the quality attributes such as sensory quality and nutritional value, as well as controlling the microbiological safety of food products. © 2014, Springer Science+Business Media New York