Positive effects of ultrasound pretreatment on the bioaccessibility and cellular uptake of bioactive compounds from broccoli: Effect on cell wall, cellular matrix and digesta

Innovative non-thermal processing: Unraveling structural and functional transformations in food macromolecules-Starch, proteins, and lipids

Thermal processing is widely used to ensure food safety and extend shelf life by inactivating microorganisms and enzymes. However, it often leads to undesirable heat-induced degradation and molecular aggregation, compromising food quality. In response, the food industry is increasingly adopting non-thermal processing technologies-such as high-pressure processing, ultrasound, pulsed electric fields, cold atmospheric plasma, and supercritical carbon dioxide-as innovative strategies to preserve or enhance the sensory and nutritional attributes of food. This review critically examines the mechanisms and effects of these emerging technologies on the physicochemical properties of major food macromolecules, including starch, proteins, and lipids. These non-thermal methods induce structural and functional modifications at both the molecular and macrostructural levels, influencing texture, flavor, and nutritional profiles. Despite growing evidence of their impact, the mechanistic understanding of cross-interactions among starch, proteins, and lipids under non-thermal treatments remains limited. Elucidating these complex interactions is crucial for optimizing processing conditions and achieving targeted functionality in food matrices. This highlights a key research gap and underscores the need for advanced analytical approaches to fully exploit the potential of non-thermal technologies in food design.

Effect of pectin structure on the in vitro bioaccessibility of carotenoids in simulated juice model

The impact of pectin structure on carotenoid bioaccessibility is still uncertain. This study aims to investigate how the different pectic polymers affected the bioaccessibility of carotenoids in a simulated juice model during static in vitro digestion. This study includes homogalacturonan (HG), which is a linear pectic polymer, rhamnogalacturonan-I (RG-I), which is a branched pectic polymer, and rhamnogalacturonan (RG), which is a diverse pectic polymer rich in RG-I, rhamnogalacturonan-II (RG-II), and xylogalacturonan domains. Juice models without pectin had the highest carotenoid bioaccessibility, suggesting pectin has negative effects on carotenoid bioaccessibility. During the intestinal phase, systems with HG showed the highest viscosity, followed by systems with RG and systems with RG-I. Systems with RG-I had lower carotenoid bioaccessibility than systems with HG and RG-II. Both the percentage of RG-I and the average side chain length of RG-I had negative correlations with carotenoid bioaccessibility. RG-I side chains with more arabinose and/or galactose might cause lower carotenoid bioaccessibility in this juice model system. This study offers valuable insights into the relationship between pectin structure and carotenoid bioaccessibility in a simulated juice model, highlighting the importance of considering pectin composition for maximizing carotenoid bioaccessibility and potential health benefits in fruit-based beverages.

Polygalacturonase treatment affects carotenoid absorption from veggie juice

The present study was conducted to investigate the effects of polygalacturonase (PG) treatment on carotenoid absorption upon digestion of HPH-treated combined peach and carrot juice (CJ) with or without the presence of lipids. Results showed that PG treatment reduced median particle diameter (D₅₀) and viscosity of CJ, and increased total carotenoid bioaccessibility by 41%. In the presence of emulsion, the bioaccessibility of carotenoids was higher and it was not significantly affected by PG treatment. Xanthophylls (lutein and zeaxanthin) had higher bioaccessibility than the more lipophilic carotenes (β-carotene and α-carotene); also, uptake in Caco-2 cells and transport of lutein and zeaxanthin were higher than for β-carotene and α-carotene. Individual carotenoids bioaccessibility was negatively correlated with their transport. All together data showed digestion and absorption processes were two independent processes: factors improving carotenoid bioaccessibility did not necessarily affect their bioavailability.

Food matrix-flavonoid interactions and their effect on bioavailability

Flavonoid compounds exhibit a wide range of health benefits as plant-derived dietary components. Typically, co-consumed with the food matrix,they must be released from the matrix and converted into an absorbable form (bioaccessibility) before reaching the small intestine, where they are eventually absorbed and transferred into the bloodstream (bioavailability) to exert their biological activity. However, a large number of studies have revealed the biological functions of individual flavonoid compounds in different experimental models, ignoring the more complex but common relationships established in the diet. Besides, it has been appreciated that the gut microbiome plays a crucial role in the metabolism of flavonoids and food substrates, thereby having a significant impact on their interactions, but much progress still needs to be made in this area. Therefore, this review intends to comprehensively investigate the interactions between flavonoids and food matrices, including lipids, proteins, carbohydrates and minerals, and their effects on the nutritional properties of food matrices and the bioaccessibility and bioavailability of flavonoid compounds. Furthermore, the health effects of the interaction of flavonoid compounds with the gut microbiome have also been discussed.HIGHLIGHTSFlavonoids are able to bind to nutrients in the food matrix through covalent or non-covalent bonds.Flavonoids affect the digestion and absorption of lipids, proteins, carbohydrates and minerals in the food matrix (bioaccessibility).Lipids, proteins and carbohydrates may favorably affect the bioavailability of flavonoids.Improved intestinal flora may improve flavonoid bioavailability.

Ultrasonic washing as an abiotic elicitor to increase the phenolic content in fruits and vegetables: A review

Ultrasonic washing has been widely applied to the postharvest storage of fruits and vegetables as a residue-free physical washing technology, which plays an important role in improving shelf-life, safety, and nutritional value. Phenolics are a large group of phytochemicals widespread in fruits and vegetables, and they have been considered potential protective factors against some diseases because of potent antioxidative properties. Previous studies have shown that ultrasonic washing can increase the phenolic content of fruits and vegetables immediately or during storage through the induction of plant stress responses, which is of great significance for improving the functional and nutritional value of fruits and vegetables. However, the mechanisms of ultrasound as an elicitor to improve the phenolic content remain controversial. Therefore, this review summarizes the applications of ultrasonic washing to increase the phenolic content in fruits and vegetables. Meanwhile, the corresponding physiological stress response mechanisms of the phenolic accumulation in terms of immediate stress responses (i.e., higher extractability of phenolics) and late stress responses (i.e., metabolism of phenolics) are expounded. Moreover, a hypothetical model is proposed to explain phenolic biosynthesis triggered by signaling molecules produced under ultrasound stress, including primary signal (i.e., extracellular adenosine triphosphate) and secondary signals (e.g., reactive oxygen species, Ca²⁺ , NO, jasmonates, and ethylene). Additionally, the techno-economic feasibility of ultrasonic washing technology is also discussed. Further, challenges and trends for further development of ultrasonic washing as an abiotic elicitor applied to the postharvest storage of fruits and vegetables are presented.