Assessment of the changes in product characteristics, total ascorbic acid, total flavonoid content, total polyphenol content and antioxidant activity of dried soursop fruit tea (Annona muricata L.) during product storage

Soursop (Annona muricata L.) fruit tea is a health-beneficial product that promotes economic development and addresses the issue of excessive agricultural waste. Prolonging the shelf-life of soursop fruit tea has been of scientific interest currently. This study evaluated the effects of three types of packaging materials of soursop fruit tea (e.g., paper, paper-combined Polyetylen (PE), and aluminum-combined PE) and different storage temperatures (5, 15, 30, and 45°C) on various product characteristics, total polyphenol content (TPC), total flavonoid content (TFC), total ascorbic acid (TAA), and 2,2-diphenyl-1-picryl hydrazyl (DPPH)/2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) free radical scavenging capacity during 4 weeks of storage. The results revealed that the sample stored in aluminum-combined PE packaging at 30°C retained most of the product's characteristics and nutritional values. This was evidenced by the moisture content of 2.49%, TAA of 3.9 ± 1.4 mg/100 g dry weight, TPC of 12.89 ± 0.47 mgGAE/g, TFC of 0.54 ± 0.004 mgQE/g, DPPH scavenging activity of 4.06 ± 0.02 mgAA/g, and ABTS scavenging activity of 13.34 ± 0.32 mgAA/g. Additionally, the microbiological quality of the sample met the standard of TCVN 9740:2013. Overall, the study highlights the importance of packaging materials and storage temperatures to maintain the nutritional quality of soursop fruit tea. It provides valuable insights into the suitable storage conditions for preserving the quality and health-promoting effects of this product.

Assessment of changes in product quality and antioxidant activity of dried soursop (Annona muricata L.) during product storage

Innovations for product preservation have attracted interest as they may increase the shelf-life of items when stored properly. In this study, the effects of various storage conditions, including four types of packaging (paper packaging, paper combined PE packaging, aluminum combined PE packaging, and plastic jar packaging) and temperatures (5, 15, 30, and 45 °C) on the quality of dried soursop were evaluated. The results demonstrated that the combination of plastic jar packaging and a storage temperature of 15 °C retained a significant portion of the initial total ascorbic acid content, total polyphenol content, and total flavonoid content. After four weeks of storage, the dried soursop preserve packaged in a plastic jar and stored at 15 °C exhibited a moisture content of 22.977 ± 0.093 %, total ascorbic acid content of 9.7 ± 0.46 mg/100gDW, total polyphenol content of 8.12 ± 0.06 mgGAE/gDW, total flavonoid content of 0.18 ± 0.02 mgQE/gDW, DPPH and ABTS scavenging activity of 0.69 ± 0.01 mgAA/gDW and 0.82 ± 0.01 mgAA/gDW, respectively. Moreover, the product meets the requirements of decision 46/2007/QD-BYT regulating the limits on biological and chemical contamination in food. The study offers valuable insights for the food industry in optimizing packaging and storage conditions to ensure the storage of quality and health-beneficial properties of this product.

Injectable thermogel incorporating reactive oxygen species scavenger and nitric oxide donor to accelerate the healing process of diabetic wounds

The healing of diabetic wounds is challenging due to redox imbalances. Herein, the thermogelling system AR-ACP hydrogel, with encapsulated biosafe nitric oxide (NO) donor L-arginine and resveratrol as an ROS scavenger, is established for sustainable wound therapy in the diabetic state. The innovated AR-ACP hydrogel dressings shows the sol-gel transition at 34 °C, allowing the hydrogel to fully cover wounds. The combination of L-arginine and resveratrol showed a prominent effect on anti-oxidative activity. The elimination of superoxide anions from the activated immune cells/oxidative cells by resveratrol maintained the NO-proangiogenic factors generated from L-arginine. Furthermore, the AR-ACP hydrogel endowed outstanding features such as haemocompatibility, non-skin irradiation as well as antibacterial activity. In the in vivo diabetic mice model, complete epidermal regeneration comparable to undamaged skin was observed with AR-ACP hydrogel. The synergy between L-arginine and resveratrol in the ACP hydrogel facilitated neovascularisation in the early stage, resulting in the higher balance in cellularity growth and collagen deposition in the dermal layer compared to control groups. Taken together, our findings demonstrate that the use of a customised ACP-based hydrogel, with the additional L-arginine and resveratrol, resulted in significant skin regeneration in the diabetic state.

Developing mango powders by foam mat drying technology

Using mango purée from overripe mangoes to produce powders helped to solve agricultural product stagnation. The research investigates the effect of thickening additives, convection drying, and heat pump drying on bioactive compounds such as total phenolic content (TPC), total flavonoid content (TFC), color, and solubility of the final product. The obtained results showed that the mixture (gum arabic and maltodextrin in the ratio 50:50 w/w) at a concentration of 15% gave a good quality powder texture when dried by hot air convection at 55°C with TPC (21.24 ± 1.58 mg GAE/g dry weight [DW]) and TFC (0.34 ± 0.02 mg QE/g DW), respectively. In addition, the product has a high solubility of 64.35%, with the highest pass-through point of 17.11.

EFFECT OF STEAM BLANCHING AND CONVECTION DRYING CONDITIONS ON COLOR, VITAMIN C, TOTAL PHENOLIC CONTENT, FLAVONOID CONTENT AND ANTIOXIDATION ACTIVITY IN SOURSOP (ANNONA MURICATA L.) LEAF TEA

Blanching and drying techniques in food processing greatly affect the bioactive values. Research into this effect on soursop leaves raw material in the processing of tea which is a plant with anti-inflammatory, anti-cancer properties. Through a steam blanching process, 4 minutes were selected for compliance with TPC (208.43 ± 0.80 mgTE/g DM) and TFC (43.21 ± 0.71 mgQuercitin/mg DM). Along with the typical antioxidant activities such as TPC, TFC, the TAA, DPPH, ABTS content decreased sharply when heated by convection drying oven at 50-65°C. About 80% of the content is lost at the highest drying temperature. In addition, the Lab* color space of the fresh sample is dark brown transformed by heat, producing a characteristic yellowish hue when extracting custard leaf tea in hot water.

Surface-enhanced Raman scattering (SERS) from low-cost silver nanoparticle-decorated cicada wing substrates for rapid detection of difenoconazole in potato

Potato is one of the most important food crops worldwide in terms of human consumption. However, potato farmers employ a variety of pesticides to protect crops from harmful insects and illnesses, and difenoconazole is a commonly used one that has severe effects on human health and the environment. Therefore, detecting difenoconazole quickly and correctly is critical. In this work, we fabricated AgNPs/cicada wing substrates using natural cicada segments, decorated with silver nanoparticles for surface-enhanced Raman scattering (SERS) measurements to detect trace amounts of difenoconazole in potatoes. Results indicated that a linear relationship with the coefficient of detection (R²) of 0.987 and the detection limit (LOD) of 0.016 ppm was observed by targeting a distinctive peak at 808 cm^-1 and logarithmic difenoconazole concentrations of 0.1 to 100 ppm. In addition, difenoconazole LODs in potatoes were 63 μg/kg, lower than those specified by the EU (0.1 mg/kg) and Vietnam (4 mg/kg) utilizing this new technique. Therefore, this proposed SERS method could be used to detect difenoconazole in potatoes at trace levels.

Study of jelly drying cashew apples (Anacardium occidentale L.) processing

Cashew apples, a by-product accrued during the manufacture of cashew nuts, have abundant nutritional values but are not widely utilized due to the presence of substances that cause acrid taste. In this study, we attempted the production of a dried jelly cashew apple product and optimized three main processing stages including blanching, osmotic, and drying. The results showed suitable conditions at 6 mm thickness in the blanching process. The osmotic process recorded a temperature of 35°C, within 1.5 h, the ratio of sugar syrup/ingredient 2:1 with sugar syrup 60 Bx, and the addition of 0.6% citric acid on the total weight of ingredients and 0.02% CaCl2. The drying process at 55°C within 267 min had the highest ascorbic acid content (TAA), total phenolic content (TPC), and content of tannin compounds (TTC) retention. These parameters refer to a product that has good organoleptic acceptability in terms of taste, acrid content, and a high ability to retain major nutrients. Furthermore, the product recovery efficiency is 21.45%. Jelly drying cashew apples (JDC) are formed to help take advantage of by-products, contributing to adding value for the cashew industry.

Optimization of the Essential Oil Extraction Process from Dong Van Marjoram (E. winitiana var. dongvanensis Phuong.) by Using Microwave Assisted Hydrodistillation, and the Bioactivities of the Oil Against Some Cancer Cell Lines and Bacteria

This study reports on the optimization of a microwave-assisted distillation process to obtain Dong Van marjoram essential oil, and the determination of its composition, content of constituents, and cytotoxic and antimicrobial activities. Using the response surface method (RSM), the optimal essential oil distillation conditions were determined as material size 0.74 (cm), water to material ratio 4.14:1 (mL/g), microwave power 302.4 (W), and distillation time 2.1 hours. At optimal conditions, the mass of Dong Van marjoram essential oil obtained was 0.887 ± 0.007 g, corresponding to a content of 0.6% essential oil in the material. GC-MS and GC-FID methods showed that the main chemical constituents of Dong Van marjoram essential oils obtained were rosefuran epoxide (44.9%), caryophyllene (10.8%), germacrene D (2.6%), and α-humulene (1.3%). The essential oil exhibited moderate inhibition against both tested cancer cell lines, with IC50 values of 23.9 µg/mL (for PC3) and 56.2 µg/mL (for A549). However, the oil exhibited strong effectiveness against three bacterial strains, Escherichia coli, Bacillus subtilis, and Staphylococcus aureus, and a yeast strain, Saccharomyces cerevisiae, with minimal inhibitory concentration (MIC) values ranged from 50 to 100 µg/mL.

Effect of targeting ligand designation of self-assembly chitosan-poloxamer nanogels loaded Paclitacel on inhibiting MCF-7 cancer cell growth

In this study, we investigated two formulations of chitosan-Pluronic P123 with different folate ligand designation for targeted delivery of Paclitaxel (PTX), in which folic acid (FA) was directly conjugated to chitosan (FA-Cs-P123) or substituted onto P123 (Cs-P123-FA). The results showed that the FA content of Cs-P123-FA was determined at 0.71 wt/wt% which was significantly higher than that of FA-Cs-P123 (0.31 wt/wt%). Two copolymers were low critical gel concentrations (CGC). FA-Cs-P123 and Cs-P123-FA nanogels performed high PTX encapsulation efficiency reaching 95.57 ± 5.51 and 92.51 ± 6.68 wt/wt%, respectively. Transmission electron microscopy (TEM) and zeta potential analysis indicated that the PTX-loaded nanogels were spherically formed around 60 nm in diameter along with positive charge. Furthermore, the PTX release profile was slow and it was controlled by the pH of the medium. In particular, in vitro biocompatibility assays indicated that both FA-Cs-P123 and Cs-P123-FA exhibited good biological compatibility with a human foreskin fibroblast cell line and well uptake efficiency into MCF-7 cancer cells. Cs-P123-FA nanogel significantly enhanced the cytotoxicity of PTX in comparison with FA-Cs-P123. The result indicates that Cs-P123-FA nanogels with a higher decorated FA content perform a better targeting efficiency; therefore, they could have great potential application towards breast cancer treatment.

Optimized extraction of polyphenols from leaves of Rosemary (Rosmarinus officinalis L.) grown in Lam Dong province, Vietnam, and evaluation of their antioxidant capacity

In the present study, the optimized solvent extraction conditions with regards to the total polyphenol content (TPC) and antioxidant capacity of rosemary leaf extract (RLE) were determined. The one-factor-at-a-time method was used to independently investigate the effect of several extraction parameters, including ethanol concentration (0–100% v/v), extraction temperature (50–80°C), extraction period (15–60 min), material–solvent ratio (1:5–1:10 g/mL), and extraction cycles (1, 2, and 3 times) on polyphenol content. Response surface methodology (RSM), in combination with a central composite design, was used to perform optimization. The following optimal conditions that gave maximal TPC were determined and experimentally verified: ethanol concentration of 65% (v/v), extraction temperature of 65°C, material–solvent ratio of 1:7.5 g/mL, extraction time of 15 min, and 2 cycles of extraction. These parameters corresponded with the TPC yield of 87.42 ± 0.25 mg gallic acid equivalent/g dried feed material (mg GAE/g DW). The optimal conditions gave a high extraction yield (337 ± 6 mg dried extract/g dried feed material) with 197.28 ± 3.11 mg GAE/g dried extract. The estimated models were strongly significant (p < 0.05) for TPC values with significant regression coefficients (R 2) of 0.9979. The obtained RLE was supposed to be the top grade of natural antioxidant with the IC50 (DPPH assays) value of 9.4 ± 0.1 μg/mL, which is higher than that of the vitamin C by just three times (IC50 = 3.2 ± 0.1 μg/mL). Current results justify RLE as a potential agent in food preservation applications.

Effects of different surface functionalization on the electronic properties and contact types of graphene/functionalized-GeC van der Waals heterostructures

Constructing vertical heterostructures by placing graphene (Gr) on two-dimensional materials has recently emerged as an effective way to enhance the performance of nanoelectronic and optoelectronic devices.