Biodegradable ultrafiltration membrane enhanced with anti-biofouling agent from Anacardium occidentale extract.

Our research focuses on developing environmentally friendly biodegradable ultrafiltration (UF) membranes for small-scale water purification in areas lacking infrastructure or during emergencies. To address biofouling challenges without resorting to harmful chemicals, we incorporate bio-based extracts, such as methyl gallate from A. occidentale leaves, a Malaysian ulam herb, known for its quorum sensing inhibition (QSI) properties. The methyl gallate enriched extract was purified by solvent partitioning and integrated into cellulose-based UF membranes (0 to 7.5% w w-1) through phase inversion technique. The resulting membranes exhibited enhanced anti-organic fouling and anti-biofouling properties, with flux recovery ratio (FRR) of 87.84 ± 2.00% against bovine serum albumin and FRRs of 76.67 ± 1.89% and 69.57 ± 1.77% against E. coli and S. aureus, respectively. The CA/MG-5 membrane showed a 224% improvement in pure water flux (PWF) compared to the neat CA membrane. Our innovative approach significantly improves PWF, presenting an environmentally friendly method for biofouling prevention in UF membrane applications.

Inhibitory effect of Malaysian coastal plants on banana (Musa acuminata colla "Lakatan"), ginger (Zingiber officinale Roscoe) and sweet potato (Ipomoea batatas) polyphenol oxidase.

Undesired browning reaction catalyzed by polyphenol oxidase (PPO) has reduced the nutritional quality and customer acceptance of the products. The inhibitory effects of six coastal plants including Sonneratia alba, Rhizophora apiculata, Syzygium grande, Rhizophora mucronata, Hibiscus tiliaceus and Bruguiera gymnorhiza on PPO in banana, sweet potato and ginger were studied based on oxidation of pyrocatechol. Banana exhibited the highest PPO activity (141,600 U), followed by sweet potato (43,440 U) and ginger (26,880 U). Banana PPO was strongly inhibited by R. apiculata (70.87%) and sweet potato PPO was strongly inhibited by S. alba (82.00%). In general, most banana PPO was the most susceptible to inhibition with all inhibitors having inhibition higher than 60.00% at 0.5 mg/ml and ginger PPO was the least susceptible with all inhibitors showing less than 50.00% inhibition at 0.5 mg/ml. Coastal plant extracts are potentially to be developed as natural inhibitors for preventing enzymatic browning of fruits and vegetables.

Inhibitory effect of chemical and natural anti-browning agents on polyphenol oxidase from ginger (Zingiber officinale Roscoe).

Food browning is undesirable as it causes deterioration in food quality and appearance. This phenomenon was related to polyphenol oxidase (PPO), which catalyzes conversion of phenolic compounds into o-quinones. The present work evaluated the use of chemical and natural anti-browning agents to prevent the browning of ginger PPO. Sodium metabisulfite (5 mM) is a better chemical inhibitor compared to l-cysteine and sodium chloride as 55.00% of ginger PPO inhibition was achieved. The percentage of inhibition increased as the concentration of anti-browning agents increases. The addition of heated onion, chili pepper and pineapple extracts exhibited a stronger inhibitory effect on ginger PPO than unheated extracts. Heated chili pepper extract was the best natural inhibitor found in this study and it inhibited the ginger PPO (47.97%) mixed-competitively. Natural anti-browning agents have potential to be used to control the browning of ginger as well as other vegetables and fruits.

Production of spray-dried honey jackfruit (Artocarpus heterophyllus) powder from enzymatic liquefied puree.

This paper presents the enzymatic liquefaction process for honey jackfruit optimized with Pectinex® Ultra SP-L and Celluclast® 1.5 L individually or in combinations at different concentrations (0-2.5% v/w) and incubation time (0-2.5 h). Treatment with combinations of enzymes showed a greater effect in the reduction of viscosity (83.9-98.8%) as compared to single enzyme treatment (64.8-87.3%). The best parameter for enzymatic liquefaction was obtained with 1.0% (v/w) Pectinex® Ultra SP-L and 0.5% (v/w) Celluclast® 1.5 L for 1.5 h. Spray drying process was carried out using different inlet temperatures (140-180 °C) and maltodextrin concentrations (10-30% w/w). Results indicated that the spray-dried honey jackfruit powder produced at 160 °C with 30% w/w maltodextrin gave the highest product yield (66.90%) with good powder qualities in terms of water activity, solubility, moisture content, hygroscopicity, color and bulk density. The spray-dried honey jackfruit powder could potentially be incorporated into various food products.

Acetic acid as a protic solvent for reducing sulphuric acid concentrations in the production of cellulose nanocrystals alongside transition metal co-catalysts.

Cellulose nanocrystals (CNC) conventionally involve highly concentrated sulphuric acid, which typically resulted in the formation of undesirable by-products. Although less corrosive mineral acids have been explored as alternatives, high concentrations are still required. In this study, CNC was successfully isolated from Leucaena leucocephala wood using mild sulphuric acid with acetic acid as protic solvent, and it was further studied with the addition of Lewis acids in the form of multivalent transition metal salts as co-catalyst. Selected divalent and trivalent transition metal salts including (Cr(NO3)3, Fe(NO3)3, Co(NO3)2, and Ni(NO3)2) were investigated. The morphology, chemical structure, particle size, and physicochemical properties of the CNCs were determined. Controlled depolymerization of cellulose was observed using transmission electron microscopy (TEM). Rod-like morphology for all CNCs was obtained during the hydrolysis process with the smallest CNC particles found at an average length of 278.1 ± 35.1 nm and a diameter of 13.4 ± 3.0 nm. The results showed that higher valence state metal ions resulted in better cellulose hydrolysis efficiency. In addition, the use of transition metal salt as a co-catalyst improved production efficiency and minimised carbonization of CNC while maintaining desired crystallinity and thermal properties.

Effects of inlet temperature and carrier concentration on spray-dried 'cempedak' (Artocarpus integer) fruit powder and its reconstitution properties.

BACKGROUND: 'Cempedak' (Artocarpus integer) is an aromatic fruit which is similar to jackfruit. Although it is rich in vitamin A and is consumed fresh, the fruit has a short shelf life. Hence, it can be converted through a spray-drying process, to form powder, which is more stable. Powder flow properties are important when considering storage, while its reconstitution characteristics are critical for the consumer to make juice from the product. METHODS: The parameters of spray-dried 'cempedak' fruit powder under study include inlet air temperature (140-180°C) and maltodextrin (DE 10) concentrations (5-15% w/w). Response surface methodology involving 14 runs was used to assess the effects of inlet temperature and maltodextrin on the powder flow properties and reconstitution properties of the spray-dried 'cempedak' powder. RESULTS: Out of the tested responses, only bulk density, change in cake height ratio, and water solubility index had a high coefficient of determination value. Inlet air temperature was found to be the main parameter to affect the bulk density, caking and water solubility index, when compared to maltodextrin concentration. By setting minimization of caking and maximization of water solubility index as the main determinants, the optimal parameters of 160°C inlet temperature and 15% (w/w) maltodextrin DE10 were generated, with a desirability of 0.697. CONCLUSIONS: The powder produced under optimal conditions (160°C and 15% w/w maltodextrin) had a low bulk density (480.01 kg/m3), low caking properties (0.17 change in cake height ratio), and a high solubility index (88.69). This indicates that the powder is stable to be stored (without caking) and will have good reconstitution when added to water.

Partial purification and characterization of polyphenol oxidase from Chinese parsley (Coriandrum sativum).

Purification and characterization of polyphenol oxidase (PPO) from Chinese parsley (Coriandrum sativum) were achieved. Crude PPO exhibited an enzyme activity of 1,952.24 EU/mL. PPO was partially purified up to 6.52x with a 10.89% yield using gel filtration chromatography. Maximal PPO activity was found at 35°C, pH 8.0 for 4-methylcatechol and at 40°C, pH 7.0 for catechol. PPO showed a higher affinity towards 4-methylcatechol, but a higher thermal stability when reacting with catechol. LCysteine was a better inhibitor than citric acid for reducing PPO activity at concentrations of 1 and 3mM in the presence of either substrate. Two 46 kDa isoenzymes were identified using SDS-PAGE. Isolation and characterization of Chinese parsley serves as a guideline for prediction of enzyme behavior leading to effective prevention of enzymatic browning during processing and storage, including inhibition and inactivation of PPO.