No abstract

Enzymatic hydrolysis has been widely applied for production of protein hydrolysate from shrimp waste and for purification of chitin. In the present study, shrimp (P. semisulcatus) head waste was hydrolysed, using a commercial proteolytic enzyme, Alcalase. In order to improve protein extraction efficiency, certain chemicals such as sodium sulphite and Triton x-100 were used along with the enzyme. When Alcalase (12 AU/kg) used alone, the yield of protein extraction was 45.1% and by using Triton x-100 (0.01 g/kg) together with Alcalase, the yield was decreased to 39%, whereas the presence of sodium sulphite (200 mmol/L) with the enzyme or with the enzyme and Triton x-100 increased the level of protein extraction to 62% and 65.1%, respectively. The resulting protein powder contained sufficient amounts of essential amino acids to be used in feed formulations. By precipitating proteins from the resulting protein extract at pH 3.1, the residual sulphite in protein powder was decreased by 97% and thus the powder can be considered suitable for animal and/or aquaculture feed formulations.

Egg yolk was partially replaced (0, 25, 50, 75, and 100%) with octenyl succinic anhydride (DSA)-modified potato starch in a reduced-fat mayonnaise formulation to curtail the problems associated with high cholesterol and induced allergic reactions. The physicochemical properties included parameters such as: pH, fat content, and emulsion stability of the formulations analyzed. The samples with 75% and 100% egg yolk substitute showed the maximum emulsion stability (>95% after two of months storage), and they were selected according to cholesterol content, particle size distributions, dynamic rheological properties, microstructure, and sensory characteristic. A significant reduction (84-97%) in the cholesterol content was observed in the selected samples. Particle size analysis showed that by increasing the amount of DSA starch, the oil droplets with the peak size of 70 µm engulfed by this compound became larger. The rheological tests elucidated that in the absence of egg yolk, DSA starch may not result in a final product with consistent texture and that the best ratio of the two emulsifiers (DSA starch/egg yolk) to produce stable reduced-fat, low cholesterol mayonnaise is 75/25. The microscopic images confirmed the formation of a stable cohesive layer of starch surrounding the oil droplets emulsified in the samples selected.Keywords: octenyl succinic anhydride; cholesterol; mayonnaise; particle size distributions; rheological characteristics; microstructure.Practical Application: The egg yolk has been partially replaced (0, 25, 50, 75,100%) by octenyl succinic anhydride (DSA)-modified potato starch in a reduced-fat mayonnaise formulation. The pH, fat content, cholesterol content and emulsion stability, particle size distributions, dynamic rheology, microstructure properties of the formulations were analyzed and the results indicated that 100% substitution of egg yolk may not be desirable because of large droplet size, low consistency and poor sensory scores. The best ratio of the two emulsifiers to produce stable reduced-fat, low cholesterol mayonnaise would be 75/25.

Extraction of ferulic acid from sugar beet pulp was carried out using three extraction solvents, sodium hydroxide (0.5, 1, 2 M), methanol and their mixture (alkaline methanolic solvent). The Ferulic acid extracted by each solvent was identified and quantified by HPLC method and the effects of solvent type, concentration and reaction time on ferulic acid solubilisation were assessed. There were differences in the contents of products extracted in the experiment conditions. The minimum amount of ferulic acid was obtained from methanolic extract while the highest concentrations (957.4 mg/L ferulic acid) were obtained employing the highest NaOH concentration (2 M), and reaction time (12 h), so phenolic compounds are better released with alkaline hydrolysis than in methanol conditions. Finally a simple procedure for the purification of ferulic acid from the alkaline extracts is presented and evaluated by FT-IR spectrum.

Pistacia atlantica subsp. Kurdica (PAK) is distributed throughout the Zagros Mountains and is indigenous to Kurdistan province in western Iran. This study focused on the composition and thermal properties of gum extracted from female and male trees from six regions of Kurdistan province. Significant differences were detected in the total protein, total ash, total carbohydrate and monosaccharaide contents according to gender and geographic region, but no significant difference was found for moisture content. Analysis of the monosaccharide composition using HPLC showed the presence of arabinose, galactose, glucose, rhamnose and xylose. Significant differences were observed for the amino acid contents of the various PAK gum samples. The most abundant amino acids were glutamic acid, aspartic acid, serine, proline and histidine; however, the relative proportions of amino acids varied considerably between samples. The results indicate that the volatile components (VoC) were significantly different between samples according to gender and region, with the predominant VoC being α-Pinene. The results of thermogravimetric analysis showed that the onset of the initial and main decomposition of the samples was at 80 °C and above 240 °C, respectively. The differential scanning calorimetry results showed that nearly all gum samples included two glass transition temperatures and heat capacity values and that nearly all of the values for the female gum samples were lower than for the male samples. which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.