An Investigation on the Effect of Harvest Time and Storage on the Quality Properties of Red Grape, the Variety of Fakhri Shahrood

Correct timing of fruit harvest may lead to increase in production efficiency, decrease in transportation and storage costs and prevent loss of quality. A 3-replicate factorial experiment based on a completely randomized design was conducted in order to investigate the effect of harvest time and storage on qualitative properties of red grape, the variety of Fakhri shahroud. Sampling was done in four stages (one sample before fruit ripening, two samples at the time of ripening and one sample after ripening) and the samples were stored at 0.5 - 1 ºC and 90 – 94% relative humidity. The results showed that with increase in storage time, the pH and taste index of the grapes decrease. A significant negative correlation between pH and acidity of fruit samples at the 99% probability level was observed. With increase in harvest time, the Bx and dextrose of the grapes increased. As harvest time was approached, the taste index of the fruits began to increase. Evaluation of interaction effect of harvest time and storage showed that samples which were harvested at 35th day, before transporting to the morgue, had the greatest taste value

The Effect of Malting Process on Physicochemical and Aerodynamic Characteristics of Two Barley Line of Golestan Province

Malting is one of the biotechnological processes that includes steeping, germination and killing of cereal. This process is performed in controlled environment in which hydrolytic enzymes are synthesized and cell wall, protein and starch of endosperm are largely digested. In this study the malting quality was evaluated in order to select the best line for malt production. The effects of malting process, on terminal velocity and physicochemical characteristics included volume, 1000 kernel weight, protein content, β-glucanase activity and cold water extract of two barely lines (EBYT-88-17 and EBYT-88-20) of Golestan Province were investigated. The experiments were done in a completely randomized design with three replications. The results of the analysis of variance showed that the type of sample (line) has a very significant impact on physicochemical and terminal velocity factors (P<0.01). Maximum and minimum volume of malt and barley corresponded to EBYT-88-20 and EBYT-88-17 respectively. The malting process reduced 1000 kernel weight, terminal velocity and increased protein amount, beta glucanase enzyme activity and cold water extraction efficiencies. The level of enzyme activity in malt resulted from EBYT-88-17 line higher than malt prepared of EBYT-88-20 line. Therefore, this line is better to use in preparation of enzyme extracts therefore in the confectionary industry, cakes and cookie

Impact of Particle Size Reduction and Carbohydrate-Hydrolyzing Enzyme Treatment on Protein Recovery from Rapeseed (Brassica rapa L.) Press Cake

The aims were to assess how particle size reduction and carbohydrate-hydrolyzing enzyme treatment influence protein recovery from rapeseed cold-pressed cake and to determine the effect of these pretreatments in protein extraction procedures varying in ionic strength, pH, and total solid content. Defatted press cake (median particle size 600 µm) was milled to 21-164 µm and 7 µm median particle sizes by pin disc milling and air-flow milling, respectively. The milled press cake samples were treated with a carbohydrate-hydrolyzing enzyme preparation, after which proteins were extracted in saline (pH 6) or alkaline (pH 12) buffer at 5 % solid content, or in water at 20 % solid content. Particle size reduction of the press cake did not influence enzyme action or protein yield, suggesting that protein release from the press cake is not physically limited by cell walls or internal cell structures. As an exception, protein release from the aleuronic cells appeared to be hindered by intact cell walls. Enzyme treatment improved protein recovery, more substantially when the extraction was carried out in water at 20 % solid content than in saline or alkaline conditions at 5 % solid content. The enzyme mediated its positive effect most probably by reducing the water holding capacity of the press cake, thereby facilitating solid-liquid separation, and releasing anionic compounds which improved protein solubility through electrostatic stabilization. The results suggest that carbohydrate-hydrolyzing enzymes are beneficial for rapeseed protein extraction at reduced water content or when no salt or alkali is added to increase protein solubility