Ultrasonics Sonochemistry最新文献

Fructus Tribuli (FT), the dried ripe fruit of Tribulus terrestris L., is recognized for its antihypertensive properties, which are enhanced by stir-frying without adjuvants. However, research on its polysaccharides with therapeutic potential remains limited. This study optimized the ultrasound-assisted extraction (UAE) of FT polysaccharides (FP) using response surface methodology, yielding a maximum extraction yield of 2.182 ± 0.29% under the conditions of liquid-solid ratio 20:1 mL/g, 51 min, 62 °C, and precipitation ethanol concentration of 95%. Subsequently, FP and stir-fried FT polysaccharides (SFP) were isolated, and their structural differences and antihypertensive effects were systematically compared. Structural analysis revealed notable differences between FP and SFP. Furthermore, the extraction resulted in a higher polysaccharide yield for SFP. In spontaneously hypertensive rats, both FP and SFP attenuated hypertension and vascular injury, modulated gut microbiota, increased short-chain fatty acids, and enhanced intestinal barrier function effects that were more pronounced with SFP. Mechanistically, both polysaccharides inhibited the aortic TLR4/MyD88 pathway. These results suggest that stir-frying modifies polysaccharide structure, thereby improving gut microbiome regulation, barrier protection, and vascular outcomes, highlighting the value of processing in enhancing polysaccharide efficacy. Thus, stir-frying amplifies therapeutic effects through bioactive macromolecular remodeling, advancing the understanding of Traditional Chinese medicine processing principles.

This review systematically summarizes the effects of ultrasound on the multi-scale structure and physicochemical properties of starch. Ultrasonic treatment can affect the fine structure, short-range and long-range ordered structures and granule structure of starch through mechanical forces, cavitation effects and accompanying thermal effects. These structure alterations collectively lead to significant changes in starch hydration behavior, pasting viscosity, thermal properties, rheological characteristics and in vitro digestibility. The extent of these effects is highly dependent on ultrasonic parameters including ultrasonic power, treatment time and temperature, as well as the combination of ultrasound with other modification methods (such as microwave processing, pullulanase treatment and alkaline modification). However, the lack of standardized ultrasonic parameters setting has limited the ability to obtain consistent and comparable conclusions. Therefore, the concept of "equivalent cavitation dose (ECD)" was innovatively introduced in this review, which was a quantitative framework integrating ultrasonic power, duty cycle, treatment duration, system temperature and medium physicochemical properties. This concept provides a reference for parameters standardization setting to achieve a more in-depth comparison among different studies. Overall, this review provides a theoretical basis for optimizing ultrasonic modification of starch, guiding the development of starch with tailored structures and functionalities to expand its application in the starch industry.

This study investigates the potential of ultrasound treatment to enhance the viability and efficacy of Lacticaseibacillus paracasei (L. paracasei) in bread production. Given the increasing consumer demand for probiotic-enriched foods, bread represents a promising vehicle for these beneficial microorganisms. Nevertheless, the high temperatures involved in traditional baking processes significantly reduce probiotic cell viability, limiting the functional effectiveness of probiotic-enriched breads. High-intensity ultrasound (HIU) has emerged as a potential strategy to enhance probiotic viability and stimulate microbial metabolic pathways, thus potentially improving probiotic performance throughout bread fermentation and baking processes. Results indicated that certain controlled ultrasound treatments promoted L. paracasei growth and metabolic activity. Specifically, treatments at lower power did not affect the immediate viability of the cells, while higher power caused a significant reduction. However, after recovery incubation, certain treated groups exhibited improved growth, indicating that specific ultrasound parameters could foster cell growth and propagation. During bread proofing, ultrasound-treated probiotics showed a slight but significant increase in cell growth. In the baking phase, while the overall viability of L. paracasei decreased, ultrasound-treated cells demonstrated enhanced heat resistance. Furthermore, the addition of L. paracasei in the dough positively impacted dough height, stability, and gas retention. Bread with added L. paracasei, both treated and untreated, revealed improvements in texture, specific volume, moisture content, and pH. In conclusion, carefully optimised ultrasound pre-treatment demonstrates substantial potential for improving probiotic-related viability and processing performance within bread systems. Further research is needed to optimise ultrasound parameters and to elucidate the underlying mechanisms responsible for the protective effects observed during bread processing.