High-intensity pulsed electric fields or thermal treatment of broccoli juice: the effects of processing on minerals and free amino acids

Effects of Novel Preparation Technology on Flavor of Vegetable-Soy Sauce Compound Condiment

Vegetables contain important bioactive substances which have unique tastes and aromas and provide beneficial effects to human health. In this study, multiflavor blended soy sauce was prepared with the juice of eight kinds of vegetables, dried shrimp boiled stock, and six kinds of commercial soy sauce as raw materials, and thermal ultrasound was used as the sterilization method. The effects of adding different formulas of vegetable and seafood stock on the basic physical and chemical parameters, nutrition, antioxidant activity, flavor, and taste of soy sauce were investigated. The results showed that the basic physicochemical indices such as pH, total acid, color, soluble solids, and amino acid nitrogen of the product with a ratio of soy sauce to vegetable-seafood stock of 1:0.5 (v/v) could meet the production standards of soy sauce, and its flavor, taste, and sensory scores were relatively good, with the highest likeability (overall acceptability). The mixed soy sauce with a ratio of 1:2 (v/v) had higher vegetable and seafood flavors, and different vegetable flavors (celery, carrot, and onion) were more obvious, but its nutritional index was relatively low. Multiflavor vegetable-soy sauce can be used for quick cooking by chefs of catering enterprises, and may be used as a seasoning bag for prefabricated dishes and convenient foods, attracting increasing attention from manufacturers and consumers.

Effect of Pulsed Electric Field on the Chicken Meat Quality and Taste-Related Amino Acid Stability: Flavor Simulation

Meat contains several amino acids related to taste, which have a significant impact on the overall acceptability of consumers. A number of volatile compounds have been studied in relation to meat flavor, but amino acids have not been fully explored in relation to the taste of raw or cooked meat. It would be interesting to find any changes in physicochemical characteristics, especially the level of taste-active compounds and flavor content during non-thermal processing such as pulsed electric fields (PEF), for commercial reasons. The effect of PEF at low intensity (LPEF; 1 kV/cm) and comparatively high intensity (HPEF; 3 kV/cm) with different pulse numbers (25, 50, and 100) was investigated on the physicochemical characteristics of chicken breast, including the free amino acid content (related to umami, sweet, bitter, or fresh pleasant taste). PEF is regarded as a "nonthermal" technology; however, HPEF induces moderate temperature rises as it increases with the treatment intensity (i.e., electric field strength and pulse number). The pH, shear force, and cook loss (%) of the LPEF and untreated samples were not affected by the treatments, but the shear force of the LPEF and untreated samples was lower than that of HPEF groups that showed PEF-induced slight structural modifications resulting in a more porous cell. In the case of color parameters, the lightness of meat (L*) was significantly higher with treatment intensity, whereas both a* and b* were unaffected by the PEF treatments. Moreover, PEF treatment significantly (p < 0.05) affected umami-related free amino acids (FAAs; glutamic acid and aspartic acid) and leucine and valine, which are precursors of flavor compounds. However, PEF decreases the level of bitter taste contributing FAAs such as lysine and tyrosine, which may prevent the formation of fermented flavors. In conclusion, both PEF treatments (LPEF and HPEF) did not adversely impact the physicochemical quality of chicken breast.