Production of ingredient type flavoured white enzyme modified cheese

Behavior of enzymes under high pressure in food processing: mechanisms, applications, and developments

High pressure processing (HPP) offers the benefits of safety, uniformity, energy-efficient, and low waste, which is widely applied for microbial inactivation and shelf-life extension for foods. Over the past forty years, HPP has been extensively researched in the food industry, enabling the inactivation or activation of different enzymes in future food by altering their molecular structure and active site conformation. Such activation or inactivation of enzymes effectively hinders the spoilage of food and the production of beneficial substances, which is crucial for improving food quality. This paper reviews the mechanism in which high pressure affects the stability and activity of enzymes, concludes the roles of key enzymes in the future food processed using high pressure technologies. Moreover, we discuss the application of modified enzymes based on high pressure, providing insights into the future direction of enzyme evolution under complex food processing conditions (e.g. high temperature, high pressure, high shear, and multiple elements). Finally, we conclude with prospects of high pressure technology and research directions in the future. Although HPP has shown positive effects in improving the future food quality, there is still a pressing need to develop new and effective combined processing methods, upgrade processing modes, and promote sustainable lifestyles.

Statistical improvement of protease production from a new isolate Bacillus thuringiensis strain-MA8 and its application in the production of enzyme-modified cheese

Enzyme-modified cheese (EMC) is a concentrated cheese flavor that is produced enzymatically from dairy substrates to provide an intense source of cheese flavor with broad applications. In this study, EMC was produced by enzymatic biotransformation from a new bacterial isolate described and molecularly identified as Bacillus thuringiensis strain-MA8. Optimization of protease production conditions using one-variable-at-a-time followed by multi-factorial (Plackett-Burman and Box-Behnken) designs increased production by 7-fold. Protease was used at different concentrations (300 and 900 U/100 g curd) as a cost-effective source of concentrated cheese flavor in the EMC preparation. Sensorial evaluation of EMC revealed that the overall acceptability, flavor, and texture were improved from the 2nd day compared to the control, and then decreased on the 4th day without any apparent bitterness. The chemical characteristics of EMC showed that the addition of protease extracts increased the total volatile fatty acids, water-soluble nitrogen, and acidity of EMC significantly (p≤0.05) compared to the control. The amino acids profile revealed that EMC1 which was treated with (300 U/100 g curd) protease had the highest essential amino acids (EAA) and EAA/total amino acids ratio. Nutritional parameters including protein efficiency ratio, biological value, and chemical score of EMC were higher than control based on Val, Met + Cys, Ile, Leu, and Phe + Tyr amino acids. Also, Scanning Electron Microscopy showed significant changes in EMC compared to the control. In conclusion, the addition of (300 U/100g curd) of protease revealed good EMC characteristics without any apparent defect.

Deproteinization of Shrimp Shell Waste by Kurthia gibsonii Mb126 immobilized chitinase

This work was aimed at immobilization, characterization, and utilization of chitinase from Kurthia gibsonii Mb126. Immobilization of Kurthia gibsonii Mb126 chitinase on glutaraldehyde treated chitosan was carried out with immobilization yield of 106%. The optimal factors of the immobilization technique such as concentration of glutaraldehyde, chitinase concentration, and immobilization time were evaluated. After optimizing process parameters of immobilization (Glutaraldehyde concentration 4%, chitinase conc. 60mg, immobilization time 30min.), the specific activity of immobilized chitinase improved to 4.3-fold compared to the free form of chitinase. Temperature and pH optima of the immobilized chitinase and free enzyme were same i.e., 7.5 and 40°C respectively. The relative activity of immobilized chitinase remained 90% at 40°C, at 50°C, and at 60°C for 120 min. In the pH range from 5.5 to 8, the immobilized chitinase retained 100% activity. The results confirmed that the pH stability and thermal stability of chitinase increased by immobilizing chitinase on chitosan. The immobilized enzyme system maintained 90% of its efficiency even after 16 successive reaction cycles. The immobilized chitinase maintained 78% of its activity even after 20 months. Fermentation of prawn shell waste with immobilized chitinase indicated a high level of deproteinization. Deproteinization experiments were carried out with 5mL (0.4 mg/mL ) of immobilized and free chitinase on 300 mg/mL of prawn shell waste for 20 days without any additional supplements at 40°C and 6.5 pH. Protein content was reduced from 38.4 to 0.8% with immobilized chitinase. Results suggests the possibility of using immobilized enzymes to remove the prawn shell waste from the environment. To the best of our knowledge there was no such study about the deproteinization of prawn shell waste using immobilized chitinase till the date.

Bovine Milk Fats and Their Replacers in Baked Goods: A Review

Milk fats and related dairy products are multi-functional ingredients in bakeries. Bakeries are critical local industries in Western countries, and milk fats represent the most important dietary lipids in countries such as New Zealand. Milk fats perform many roles in bakery products, including dough strengthening, textural softeners, filling fats, coating lipids, laminating fats, and flavor improvers. This review reports how milk fats interact with the ingredients of main bakery products. It also elaborates on recent studies on how to modulate the quality and digestibility of baked goods by designing a new type of fat mimetic, in order to make calorie- and saturated fat-reduced bakery products. It provides a quick reference for both retailers and industrial manufacturers of milk fat-based bakery products.