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In recent years, many advances have been made in improving the biocatalytic activities of enzymes. Interaction of enzymes and macromolecules have important role in stabilization of enzyme’s structure and function. Lysozyme lyses the bacterial cell wall by splitting ß (1–4) linkages between N-acetylmuramic acid and N-acetylglucosamine of the peptidoglycan in bacterial cell walls. Tragacanth is a polysaccharide obtained from exudates of the species of Astragalus. It is a very complex heterogeneous anionic polysaccharide of high molecular weight. Tragacanth consists of two main fractions: a water-insoluble component called bassorin, and a water-soluble component called tragacanthin. The aim of this investigation was to attach tragacanthin (water-soluble component of tragacanth) to lysozyme by Maillard reaction. The covalent attachment of this hydrocolloid with lysozyme was confirmed by SDS-PAGE and ion exchange chromatography. The conjugates exhibited improved solubility, foaming and emulsion properties. In addition, thermal stability of lysozyme in this conjugate was increased significantly. According to these results, attachment of lysozyme to tragacanthin can increase the application of this hydrocolloid as a functional component and lysozyme as a natural antimicrobial component in food and pharmaceutical industry.

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Verjuice is a popular fruit juice mainly consumed as salad dressing. However, there is very little information regarding its characteristics. The objective of the present study was to determine verjuice and its concentrate physicochemical properties during storage at 4 °C. Firstly, verjuice characteristics such as pH, acidity, specific weight, density, total soluble solids, total solid, reducing sugar content, ash, rare minerals, vitamin C , phenolic content and antioxidant activity were evaluated. In the next phase variation of acidity, pH, total solid and colour parameter (L, a, b) and total phenolic content of pasteurized concentrate verjuice during 6 months storage at 4 °C were assessed. Findings revealed that not only verjuice has a high acidity value but also it is a good source of bioactives such as vitamin C, antioxidant and phenolics components. Storing the concentrate at 4 °C resulted in reduced acidity, phenolic content, parameter L and b but increased value of parameter a, and total solid.

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The aim of this study was to prepare tortilla from oat flour and optimize the physical quality of the resulting product. Inactivated the lipase and peroxidase enzymes in the oat grains were processed during thermal process operation to prevent lipid rancidity and the oat flour was prepared. At the next stage, tortilla was prepared from oat flour.To improve the texture of tortilla, whey, gluten and mono di glyceride isolates were added to oat flour. The effect of the additives was investigated during tissue stress, fragility resistance and colorimetry tests. According to the results,with increasing gluten level, the fragility resistance of the produced sample was increased.Also, with an increase in the dough baking temperature of 140 to 160 degrees Celsius, the brightness of the produced sample was reduced. Then, the produced samples were compared with two commercial samples of "Pringles" and "Tordilla",which were prepared from maize flour,and chemical compounds, texture meter,amino acid content,colorimetry and organoleptic characteristics were studied. According to the results obtained at 5% level, the Tortilla from oat showed no significant difference in terms of the texture and color quality with the two commercial samples of Pringles and Tordilla as well as had higher essential amino acids, low fat and high quality protein content.Also,the tortilla and two commercial samples of  Pringles and Tordilla were evaluated by the assessors in terms of the indicators of crispiness, color, flavor and taste,which had a significant difference at the level of 5%, so that the highest score was for Pringles, Tortilla and Tordilla, respectively.