Punnanee Sumpavapol

Coffee silverskin (CS), the main by-product of coffee roasting production, contains various valuable bioactive compounds in its chemical compositions. Hydrothermal water extraction (HDTE) is one of the promising techniques for valorizing the organic fraction of CS into functional bioactive ingredients, which can be further exploited in various applications. This study aimed to evaluate the hyaluronidase and α-glucosidase inhibition activities of the CS extracts obtained under optimized water extraction conditions. Process optimization was performed using central composite design response surface methodology (CCD-RSM) with a broader range of extraction temperatures (25, 137.5, and 250 °C), reaction times (5, 38.5, and 72 min), and solid-to-liquid ratios (1:10, 1:80, and 1:150). The highest yield of 39.62% was obtained at 137.5 °C, with a reaction time of 72 min and an S/L ratio of 1:80. The total caffeoylquinic acid contents (T-CQA) were quantified based on the sum of three major isomers, including 3-CQA, 4-CQA, and 5-CQA. The results revealed that the highest T-CQA (2.76 ± 0.20 mg/g CS) was significantly obtained (p < 0.05) by subcritical water extraction (SWE) at 143.2 °C with an S/L ratio of 1:10 and an extraction time of 10.41 min. At such conditions, the total phenolic content (TPC), antioxidant properties (AP), and caffeine were 96.13 mg gallic acid equivalence per gram (GAE/g) CS, 20.85 ± 0.17 mg Trolox equivalence per gram (TE/g) CS, and 10.84 ± 1.25 mg/g CS, respectively. The 50% inhibition capacity (IC50) of hyaluronidase and α-glucosidase inhibition of the CS extracted were 5.00 mg/mL and 9.00 mg/mL, respectively. Our results supported the potential direct or indirect applications of CS, such as hydrothermal CS extract (HDT-CSE), in functional food or drinks. Repurposing CS residue to manufacture new products can efficiently reduce the amount of organic waste in landfills, thus conserving resources and energy and contributing to a lower overall carbon footprint in coffee production.

The light mango or “Ma-Muang Bao” (Mangifere indica L. var.) is a native mango species originating from Malaysia and southern Thailand. The whole Ma-Muang Bao fruit, except peels, is popular as both a raw and ripe fruit for consumption, as well as being used in various processed food products. This study aims to transform the peel of a specific mango variety, which is a byproduct of the agro-industrial sweet, pickled mangoes industry, into a valuable bioactive ingredient for healthcare products. This is achieved through the establishment of a standardized mangiferin-rich mango peel extract (SMPE). Employing the Box–Behnken design (BBD) within the framework of response surface methodology (RSM), an optimal microwave-assisted extraction procedure was developed. A total of 27 experiments, each with four independent variables, including solvent ratio, extraction power, extraction time, and ethanol (EtOH) ratio, were conducted to optimize the extraction method in terms of mangiferin content and extraction yield. The optimized extraction conditions encompassed a solvent ratio of 120 mL EtOH/100 g sample, an extraction power of 450 W, an extraction time of approximately 4.3 min, and an EtOH ratio of 69.44% (EtOH in water). Small-scale extractions were carried out using the following specified parameters: solvent ratio of 120 mL, extraction power of 450 W, extraction time of 4 min, and EtOH ratio of 70% EtOH. These extractions yielded an extract with a mangiferin content of 27.24 ± 2.05 mg/g and an extraction yield of 3.71 ± 0.17% w/w. Notably, these outcomes were better from the mangiferin content of 19.62 mg/g and a yield of fresh peel of 5.61% estimated through BBD analysis. Furthermore, a pilot-scale extraction was performed using 7 kg of fresh mango peel and 70% EtOH (8.4 L) for 4 min, resulting in an extract with a mangiferin content of 51.85 ± 0.35 mg/g and a fresh peel yield of 4.35% w/w. This method emerges as the most suitable for mango peel extraction and forms the basis of the SMPE. The results from biological activities highlight the potential use of SMPE as the active ingredient for cosmeceutical or healthcare products for wound-healing and skin-brightening agents. Additionally, the knowledge from this study presents an alternative approach to various plant sources and sustainable extraction methods for the herbal extract industry.

Phenolic compounds from cashew (Anacardium occidentale L.) leaves were extracted using ethanol with the aid of ultrasonication. Three independent variables, including ultrasound amplitude, time, and ethanol concentration, were used for response surface methodology (RSM) along with the central composite design (CCD). Under the optimized condition (70% amplitude; 40 min; 80% ethanol), the extraction yield and total phenolic contents were 24.50% and 431.16 mg GAE/g dry extract, respectively. Cashew leaf extract (CLE) had the lower minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against Shewanella sp. than P. aeruginosa. The release of K⁺ and Mg²⁺ ions from damaged cell membranes with a coincidental decrease of TTC dehydrogenase activity were augmented when treated with CLE. In addition, scanning electron microscopic (SEM) image revealed deformations and perforation of cell walls of bacteria treated with CLE. The dominant compounds in CLE were amentoflavone, quercetin, and its glycosides. Based on microbial challenge test, the growth of P. aeruginosa and Shewanella sp. inoculated in tilapia slices were inhibited by CLE at 400 and 600 ppm within 15 days of refrigerated storage.

Sweet pickled mango named Ma-Muang Bao Chae-Im (MBC), a delicacy from the Southern part of Thailand, has a unique aroma and taste. The employed immersion processes (brining 1, brining 2, and immersion in a hypertonic sugar solution, sequentially) in the MBC production process bring changes to the unripe mango, which indicate the occurrence of metabolic profiles alteration during the production process. This occurrence was never been explored. Thus, this study investigated metabolic profile alteration during the MBC production process. The untargeted metabolomics profiling method was used to reveal the changes in volatile and non-volatile metabolites. Headspace solid-phase micro-extraction tandem with gas chromatography quadrupole time of flight (GC/QTOF) was employed for the volatile analysis, while metabolites derivatization for non-volatile analysis. In conclusion, a total of 82 volatile and 41 non-volatile metabolites were identified during the production process. Terpenes, terpenoids, several non-volatile organic acids, and sugars were the major mango metabolites that presented throughout the process. Gamma-aminobutyric acid (GABA) was only observed during the brining processes, which suggested the microorganism’s stress response mechanism to an acidic environment and high chloride ions in brine. Esters and alcohols were abundant during the last immersion process, which had an important role in MBC flavor characteristics. The knowledge of metabolites development during the MBC production process would be beneficial for product development and optimization.