Recent advance in modification strategies and applications of soy protein gel properties.

Soy protein gel can be developed into a variety of products, ranging from traditional food (e.g., tofu) to newly developed food (e.g., soy yogurt and meat analog). So far, efforts are still needed to be made on modifying the gel properties of soy protein for improving its sensory properties as animal protein-based food substitutes. Furthermore, there is always a need to regulate its gel properties for designing novel and tailored products of soy protein gels due to the fast-growing plant protein-based product market. This review gave an emphasis on the latest modification strategies and applications of gel properties of soy protein. The modifying methods of soy protein gel properties were reviewed from an aspect of composition or processing. Compositional modification included changing protein composition and gelling conditions and using additives, whereas processing strategies can be achieved through physical, chemical, and enzymatic treatments. Several compositional modification and processing strategies have been both proven to alter the gel properties of soy protein effectively. So far, soy protein gel has been applied in the field of food and biomedicine. In the future, more mechanistic studies on the modification methods are still needed to facilitate the full application of soy protein gel.

Analytical performance of three diagnostic reagents for HBsAg on an automatic ELISA analyzer.

PURPOSE: We conducted performance tests of three HBsAg ELISA diagnostic reagents using an Addcare 600 (Yantai Addcare Bio-tech Limited Company) and studied the consistency between the qualitative results and chemiluminescent microparticle immunoassay (CMIA) results. METHODS: Diagnostic kits (ELISA) for HBsAg manufactured by INTEC ("A"), KHB ("B") and Wantai ("C") were tested on an Addcare 600 to evaluate their intermediate precision, repeatability, and C50. Furthermore, three ELISA detection systems and a quantitative test kit for HBsAg (Abbott) were employed to screen 1000 serum samples, while CMIA reactive samples were used to perform the confirmatory tests. The evaluation indexes of the ELISA reagent performances were calculated. RESULTS: The intermediate precision and repeatability of each system were <14% and <9%, respectively, while C50 was 0.105-0.115 IU/mL. The sensitivities of A, B, and C were 98.70%, 99.28%, and 99.13%, respectively, while their specificities were 98.06%, 99.03%, and 97.42%, respectively. The Youden indexes were 96.76%, 98.31%, and 96.55%, respectively, while the kappa values were 0.965 (P=.000), 0.981 (P=.000), and 0.967 (P=.000), respectively. CONCLUSION: The combination of Addcare 600 with the three reagents could meet the clinical requirement. Reagent B demonstrated the best performance. Although the results consistency among the three systems and CMIA was good, our findings suggest that ELISA should be combined with a confirmatory test to exclude false-positive and false-negative results caused by low HBsAg levels.