Comparative physiological and transcriptomic analysis reveals an improved biological control efficacy of Sporidiobolus pararoseus Y16 enhanced with ascorbic acid against the oxidative stress tolerance caused by Penicillium expansum in pears.

Sporidiobolus pararoseus Y16, a species of significant ecological importance, has distinctive physiological and biological regulatory systems that aid in its survival and environmental adaptation. The goal of this investigation was to understand the complex interactions between physiological and molecular mechanisms in pear fruits as induced by S. pararoseus Y16. The study investigated the use of S. pararoseus Y16 and ascorbic acid (VC) in combination in controlling blue mold decay in pears via physiological and transcriptomic approach. The study results showed that treatment of S. pararoseus Y16 with 150 µg/mL VC reduced pears blue mold disease incidence from 43% to 11%. Furthermore, the combination of S. pararoseus Y16 and VC significantly inhibited mycelia growth and spore germination of Penicillium expansum in the pear's wounds. The pre-treatment did not impair post-harvest qualities of pear fruit but increased antioxidant enzyme activity specifically polyphenol oxidase (PPO), peroxidase (POD), catalase (CAT) activities as well as phenylalanine ammonia-lyase (PAL) enzyme activity. The transcriptome analysis further uncovered 395 differentially expressed genes (DEGs) and pathways involved in defense mechanisms and disease resistance. Notable pathways of the DEGs include plant-pathogen interaction, tyrosine metabolism, and hormone signal transduction pathways. The integrative approach with both physiological and transcriptomic tools to investigate postharvest pathology in pear fruits with clarification on how S. pararoseus Y16 enhanced with VC, improved gene expression for disease defense, and create alternative controls strategies for managing postharvest diseases.

Optimized pressurized hot water extraction, HPLC/LC-MS characterization, and bioactivity of Tetrapleura tetraptera L. dry fruit polyphenols.

Despite the global preference for green extraction methods in the recovery of plant bioactives, Tetrapleura tetraptera fruit polyphenols (TTP) are yet to receive considerable attention. For the first time, pressurized hot water extraction (PHWE) of TTP was optimized for total phenol content (TPC) and antioxidant activity (AA) using the Box Behnken design of response surface methodology. Predictor variables were time, temperature, and liquid-to-solid ratio. An optimum solution with a desirability of 0.805 was selected and parameters were 43 min, 220°C, and 60 ml g-1 liquid-to-solid ratio, yielding TPC of 8.92 mg gallic acid equivalent per gram of sample on dry weight basis (GAE g-1  dw-1 ) and AA of 70.35%. Purified, optimized TTP were characterized and quantified using HPLC/LC-MS. PHWE mainly extracted rutin (379.04 µg g-1 ), cyanidin-3-O-glucoside (chloride) (299.55 µg g-1 ), naringenin 7-O-glucoside (240.11 µg g-1 ), p-coumaric acid (177.28 µg g-1 ), isorientin (150.43 µg g-1 ), and gallic acid (118.06 µg g-1 ) whereas cyanidin-3-O-glucoside (chloride) (83.27 µg g-1 ), protocatechuic acid (61.37 µg g-1 ), rutin (28.03 µg g-1 ), and gallic acid (22.62 µg g-1 ) were mainly extracted by hot water extraction, which was a control. PHWE-obtained TTP showed higher cellular antioxidant activity, cytotoxicity in human liver cancer cell lines (HepG2), and antimicrobial property against Escherichia coli, Staphylococcus aureus, and Bacillus subtilis than control. The potential mechanisms underlying the biological activities of some of the major polyphenols extracted were briefly discussed. Considering the wide use of the T. tetraptera (TT) fruit in Africa in foods and medicine, the use of more efficient green extraction methods such as PHWE is recommended. PRACTICAL APPLICATION: This study serves as a baseline for optimizing pressurized hot water extraction, purification, identification, and quantification of Tetrapleura tetraptera polyphenols (TTP) and their biological activities, being the first of its kind. The varied biological effects shown can be exploited further for applications of TTP as nutraceutical agents and preservatives in foods in different forms. Also, the high amounts of gallic acid and other phenolic acids and flavonoids confirmed in this study make TTP good candidates for the development of metal-phenol network nanoparticles to enhance adequate solubility and distribution in food systems in light of the above proposed applications.

Dietary Polyphenols and Obesity: A Review of Polyphenol Effects on Lipid and Glucose Metabolism, Mitochondrial Homeostasis, and Starch Digestibility and Absorption.

Obesity is a major global public health concern, limiting socio-economic development and human productivity. As studies focus on finding sustainable solutions to this challenge, polyphenols have shown promising results and have become a research focus. This is mainly because of associated lower risks of side effects with their use, compared to synthetic pharmaceuticals. In this study, the anti-obesity potentials of dietary polyphenols have been reviewed. Using a narrative approach, the biological activities of polyphenols and their influence on energy metabolism and mechanisms are discussed. Specifically, their roles in insulin-dependent glucose uptake, insulin sensitivity, lipid metabolism and storage in adipocytes, starch digestibility, and regulation of mitophagy and mitogenesis in muscle cells and adipocytes, were considered. After considering the major findings of many related studies, it was confirmed that polyphenols can prevent and ameliorate obesity by fighting insulin resistance (IR) induced by pro-inflammatory cytokines, scavenging reactive oxygen species (ROS) and limiting their effects, and by regulating the expression and/or activity of key enzymes along relevant pathways. More human studies are needed to reveal more about the anti-obesity effects of dietary polyphenols and their effective doses in humans.

Effects of pretreatment and type of hydrolysis on the composition, antioxidant potential and HepG2 cytotoxicity of bound polyphenols from Tartary buckwheat (Fagopyrum tataricum L. Gaerth) hulls.

This study investigated the effects of ultrasound assisted-subcritical water (U-SW), subcritical water (SW), ultrasound (U) and hot water (HW) pretreatments and acid hydrolysis (AH) and alkaline hydrolysis (AlkH) on the phenolic composition, antioxidant potential and cytotoxicity of Tartary buckwheat hull extracts. The Folin Ciocalteu assay and HPLC-MS were used to characterize and quantify phenolics of the extracts. The ABTS, FRAP and TEAC assays were used to measure antioxidant activity and the MTT assay was used to measure cytotoxicity of the extracts in HepG2 human liver cancer cells. Results showed that U-SW gave the best AH yield of phenolics (128.45), followed by SW (85.82) and U (64.70), compared to the control, HW (35.82 mgg-1). The same trend was observed for phenols extracted using AlkH. U-SW had the highest antioxidant activity, followed by SW and U regardless of hydrolytic method used. Cytotoxicity followed a similar trend with U-SW and SW being the most cytotoxic to liver cancer cells, followed by U, with the least being HW. The findings suggested that plant materials such as Tartary buckwheat hulls can be pretreated with U-SW, SW and U prior to hydrolytic recovery of bound polyphenols. Also, AH was more efficient than AlkH for phenol extraction, and gave extracts with higher antioxidant activity and cytotoxicity in HepG2 liver carcinoma cells. This application allows for beneficial usage of agricultural biomass and help diversify income sources and products for industry.

Ultrasound-, subcritical water- and ultrasound assisted subcritical water-derived Tartary buckwheat polyphenols show superior antioxidant activity and cytotoxicity in human liver carcinoma cells.

The effects of ultrasound-assisted (UAE), subcritical water (SWE) and ultrasound assisted-subcritical water (UA-SWE) treatments on tartary buckwheat polyphenol yield, composition, antioxidant activity and cytotoxicity in human liver carcinoma cells were studied. Folin Ciocalteu assay was used to measure total free phenol content (TFPC), and ABTS, DPPH, FRAP and TEAC assays were used to measure antioxidant activity (AA). Polyphenol characterization was done by LC-MS and cell antioxidant activity (CAA) and cytotoxicity were done using the 2,2'-Azobis-(2-amidinopropane) dihydrochloride [ABAP] and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide [MTT] assays respectively. The highest polyphenol yield was obtained by SWE (53.3 mg g-1), followed by UA-SWE (31.8 mg g-1), UAE (19.3 mg g-1) and HWE (4.2 mg g-1). Also, SWE had the highest TFPC (7.9 mgGAE/gdw). UAE and UA-SWE showed no differences with TFPC being 6.6 and 6.8 mgGAE/gdw, respectively. The control method (HWE) had the largest number of phenolic compounds identified (25), followed by UAE, SWE and UA-SWE which had 20, 13 and 11 phenolics respectively. Beside phenolic acids, all treatments extracted a number of flavonoids such as flavan-3-ols (catechin-7-O-glucoside, epigallocatechin-3-gallate, epigallocatechin, epicatechin), flavonols (kaempferol-3-O-glucoside, kaempferol, kaempferol-3-rutinoside, rutin, quercetin, quercetin-3-O-glucuronide hyperin), flavones (vitexin, isovitexin, orientin, isoorientin) and anthocyanins (cyanidin-3-O-rutinoside, Cyanidin 3-O-galactoside, cyanidin-3-O-glucoside). SWE gave the highest AA for all tests. However, the AA of those obtained by UAE and UA-SWE did not vary (P < 0.05), but were higher than HWE. Different extracts had best AA at different concentrations (HWE, 300; UAE, 250; SWE, 150; UA-SWE, 200 µg/mL). The IC50 of AA were 270.8 ± 21.3, 198.1 ± 16.0, 97.9 ± 13.5, and 150.4 ± 12.8 µg/mL, respectively for HWE, UAE, SWE and UA-SWE. Generally, SWE and UA-SWE showed the highest cytotoxic activities, followed by UAE, with HWE being the lowest. IC50 of cytotoxicity were 76.1 ± 3.3, 79.5 ± 7.0 and 92.6 ± 4.9 µg/mL for SWE, UA-SWE and UAE, respectively. SWE is a promising method for polyphenol extraction and its combination with ultrasound should be optimized for high yield and conservation of bioactivity.

Binding affinity, antioxidative capacity and in vitro digestion of complexes of grape seed procyanidins and pork, chicken and fish protein.

Studies have reported that procyanidins can interact with proteins, thereby affecting their structure, function, and bioaccessibility. In this paper, we investigated the interaction between grape seeds procyanidins (GSP) and animal source protein (from pig, chicken and fish), and the effects on the protein structure, antioxidant capacity and bioaccessibility of GSP. Fluorescence results showed that the binding constant of GSP-protein complex was 10-104 M-1, and the main forces were van der Waals force, hydrogen bonds and hydrophobic interactions. The antioxidant capacity of GSP was masked by GSP-protein complexes formed. The circular dichroism indicated that GSP had an effect on the content of α-helix and ß-sheet in the secondary structure of pork and chicken proteins, but had little effect on the secondary structure of fish protein. The results showed that the protein can bind to GSP and affect its antioxidant activity and bioaccessibility. This study can provide reference for further study on the digestion and absorption of the complexes and offer health guidance in the preparation of diets.

Structural characterization and physicochemical properties of arrowhead resistant starch prepared by different methods.

Resistant starch (RS) served as a novel functional ingredient has attracted much attention. In this paper, the structure and physicochemical properties of arrowhead resistant starch (ARS) prepared by subcritical water (SW-ARS), ultrasound-subcritical water (USW-ARS), autoclaving (AM-ARS) and ultrasound-autoclaving (UAM-ARS) were investigated. The results showed that the structure of starch granules was completely disrupted and the size of starch granules was obviously increased. SW-ARS, USW-ARS, AM-ARS and UAM-ARS exhibited a B-type crystallinity pattern with different degree of crystallinity. UAM-ARS displayed the highest molecular order with the highest degree of double helixes while SW-ARS, USW-ARS and AM-ARS showed a lower degree of molecular order than that of arrowhead native starch (ANS). The ANS and ARS prepared by four methods possessed high gelation enthalpy in which UAM-ARS had the highest gelation enthalpy, indicating that they had excellent thermostability. Therefore, ANS and the resulting ARS may be a promising starch-based material. All these results are expected to provide information on the preparation and application of ANS and ARS.

Effect of multi-frequency countercurrent ultrasound treatment on extraction optimization, functional and structural properties of protein isolates from Walnut (Juglans regia L.) meal.

This study evaluated the effects of ultrasound treatment on walnut meal protein (WMP) extraction and techno-functional properties. The Box-Behnken Design (BBD) was adopted for the optimization of the traditional and ultrasound-assisted extraction (UAE) processes. Standard protocols were used to assay the techno-functional characteristics. The extraction models' statistical results exhibited adequacy with the least desirability index of 95.8%. The UAE enhanced the WMP extraction yield, purity, and chemical score by 30.15%, 16.27%, and 9.74%, respectively, while reducing the extraction time by 25% over the control. The emulsion and foam stabilities and bulk density increased by 34.5%, 39.8%, and 6.1%, respectively, over the control. The α-helix decreased while ß-sheet, ß-turns and random coil secondary structure components increased significantly (p < .05) by 95.76%, 101.3%, 105.1%, and 85.7% correspondingly. The dual-frequency combination (20/40 kHz/kHz) was the best frequency mode. WMP could serve as a functional additive in manufactured foods as texture and flavor enhancer. PRACTICAL APPLICATIONS: Walnut meal protein (WMP) has a well-balanced amino acid profile and its economic use could be practically increased as a food ingredient by ultrasound-assisted extraction. By this technique, WMP could be employed for the development of enhanced food ingredients rather than being discarded as animal feed. This study showed a positive effect of ultrasonic-assisted alkaline pretreatment on WMP extraction, functionality and structure characteristics. In addition to process improvement, ultrasound is energy efficient and environmentally friendly. Therefore, the applicability of this technique to improve the functionality of plant proteins from industrial by-products to be included in food products is promising.

Advances in ultrasound assisted extraction of bioactive compounds from cash crops - A review.

Bioactive compounds in cash crops can be obtained from horticulture, oil and medicinal crops sources. Conventional extraction methods have disadvantages such as low extraction rate, large solvent consumption, high energy consumption and long production cycle. Ultrasonic-assisted extraction is a novel, green and rapid developing technology, which is suitable for up scaling and improving the extraction efficiency of bioactive compounds. Ultrasound mainly acts by producing cavitation bubbles in biological matrix. It has inclusively been reported for achieving high yields and extraction rates of bioactive compounds. Moreover, it can bring remarkable economic and environmental benefits, and has great potential for development and application. This review summarizes the mechanisms, effects of ultrasonic-assisted extraction, ultrasonic devices, and their application in bioactive compounds extraction from cash crops. The future perspective of ultrasound technology is also discussed, which will help to better understand the complex mechanism of ultrasonic-assisted extraction and further guide its application in cash crops.