Physiochemical properties of Sarawak's adapted Liberica coffee silverskin utilizing varying solvents.

This study aimed to investigate the physiochemical properties of Sarawak's adapted Liberica coffee silverskin (CS) using multiple solvents (distilled water, methanol, and ethanol) and its impact on the total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activities of the CS. The results showed that the highest TPC was observed in the methanol extract (15.24 ± 0.65 mg GAE/g), while the highest TFC was recorded when extracted with ethanol (25.14 ± 0.59 mg QE/g). The DPPH activity was also found to be highest in the ethanol extract (83.85 ± 1.78%), concurred by the results in the FRAP assay as the highest reduction was also in ethanol (11.40 ± 18.57 µmol FSE/g). These findings demonstrate that the bioactive compounds of CS extracted can be greatly influenced by the choice of solvent while highlighting the potential for Sarawak's adapted Liberica CS to be further harnessed into a value-added product and enabling a better by-product waste management.

Microwave-assisted extraction of bioactive compounds from Sarawak Liberica sp. coffee pulp: Statistical optimization and comparison with conventional methods.

Coffea liberica, commonly known as Liberica coffee, is a kind of coffee that originated in Liberia, a West African country. It is considered a less-known coffee bean variety, which accounts for less than 2% of commercially produced coffee worldwide. In this study, the influences of optimization of microwave-assisted extraction (MAE) on the total phenolic content (TPC), total flavonoid content (TFC), and total carbohydrate content (TCC) of bioactive compounds extracted from Sarawak Liberica sp. coffee pulp were studied. Response surface methodology was adopted with a face-centered central composite design to generate 34 responses by taking three microwave parameters into consideration, microwave power (watt), time of irradiation (second), and solvent-to-feed ratio as independent variables. As a result, the findings revealed that optimum extraction conditions were conducted as follows: microwave power of 700 W, time of irradiation of 180 s, and solvent-to-feed ratio of 86.644:1. While under optimal extraction conditions, MAE outperformed conventional maceration extraction in terms of extraction efficiency and had no significant difference (p < .05) with Soxhlet extraction on the extraction of TPC (12.94 ± 2.25 mg GAE/g), TFC (9.84 ± 0.38 mg QE/g), and TCC (876.50 ± 64.15 mg GE/g). Present work advances the usage of Sarawak Liberica sp. coffee for the development of functional products and aids in reducing environmental pollution by utilization of coffee pulp waste.

Onion Essential Oil-in-Water Emulsion as a Food Flavoring Agent: Effect of Environmental Stress on Physical Properties and Antibacterial Activity.

Plant essential oils (EOs), which are acknowledged as generally recognized as safe (GRAS) by the Food and Drug Administration (FDA), have the potential to be used as a flavoring agent. However, there are limitations to some EOs, such as low water solubility and high volatility, which limit their application in food technology. This study was conducted to develop onion (Allium cepa) EO as a flavoring agent and determine its stability against environmental stress via an emulsification technique, with different concentrations of sodium caseinate, as a delivery system. Emulsions containing onion EO were prepared using different concentrations of sodium caseinate (3, 5, and 7% w/w) via the solvent-displacement technique. The physical properties (average droplet size, color, turbidity, and stability measurement) and antibacterial activity (agar disk diffusion method) of emulsions were then determined. Results show that emulsion with 7% (w/w) sodium caseinate was the most desirable sample in terms of physical properties and antibacterial activity. Hence, it was selected for environmental stress studies (i.e., thermal processing, freeze-thaw cycles, and ultraviolet (UV) exposure). Results revealed that all types of environmental stresses had significant (p < 0.05) effects on droplet size, color, turbidity, and stability. Generally, the environmental stresses increased the droplet size except in the freeze-thaw cycle case, while all stresses decreased the stability and lightness. All types of environmental stress treatment did not show a significant (p < 0.05) effect on antibacterial activity enhancement against Salmonella Typhimurium and Listeria monocytogenes except in the case of UV treatment against L. monocytogenes. Therefore, the present work has demonstrated the potential use of emulsion as an encapsulation and delivery system of EO flavors for food applications.

Detection of Cryptosporidium and Cyclospora Oocysts from Environmental Water for Drinking and Recreational Activities in Sarawak, Malaysia.

Cryptosporidiosis and cyclosporiasis are caused by waterborne coccidian protozoan parasites of the genera Cryptosporidium and Cyclospora, respectively. This study was conducted to detect Cryptosporidium and Cyclospora oocysts from environmental water abstracted by drinking water treatment plants and recreational activities in Sarawak, Malaysia. Water samples (12 each) were collected from Sungai Sarawak Kanan in Bau and Sungai Sarawak Kiri in Batu Kitang, respectively. In addition, 6 water samples each were collected from Ranchan Recreational Park and UNIMAS Lake at Universiti Malaysia Sarawak, Kota Samarahan, respectively. Water physicochemical parameters were also recorded. All samples were concentrated by the iron sulfate flocculation method followed by the sucrose floatation technique. Cryptosporidium and Cyclospora were detected by modified Ziehl-Neelsen technique. Correlation of the parasites distribution with water physicochemical parameters was analysed using bivariate Pearson correlation. Based on the 24 total samples of environmental water abstracted by drinking water treatment plants, all the samples (24/24; 100%) were positive with Cryptosporidium, and only 2 samples (2/24; 8.33%) were positive with Cyclospora. Based on the 12 total samples of water for recreational activities, 4 samples (4/12; 33%) were positive with Cryptosporidium, while 2 samples (2/12; 17%) were positive with Cyclospora. Cryptosporidium oocysts were negatively correlated with dissolved oxygen (DO).