Physicochemical and antioxidant properties of raw honeys from Malaysia were used as markers for determining its entomological source of bee species of Apis dorsata, Apis mellifera, Apis cerana, or Heterotrigona itama. Physicochemical properties of moisture content, water activity, specific gravity, viscosity, pH, free acidity, electrical conductivity, colour (L*, a* and b*), colour intensity, and antioxidant properties including the DPPH free radical scavenging activity power (1/IC50), ascorbic acid equivalent antioxidant content (AEAC), ferric ion reducing antioxidant power (FRAP), and total phenolic content (TPC) were measured and analysed. Honeys were classified into two major groups of those from honey bees (Apis spp.) and Trigona stingless bees (Heterotrigona itama) from its physicochemical and antioxidant properties using hierarchical cluster and principal component analyses. The Kelulut honey produced by stingless bees, Heterotrigona itama was differentiable from honeys from the regular honey bee species, the Apis spp. with characteristics of high moisture content of 33.24 g/100 g, free acidity of 136.8 meq/kg, colour intensity of 990.3 mAU, AEAC of 26.64 mg/100 g, and FRAP of 41.95 mg AAE/100 g. Honey classification by its entomological origin helps in honey identification and it reduces honey fraudulence.

In food packaging, smart indicator films based on natural resources have greatly attracted researchers to minimize the environmental issues as well as to satisfy consumer preferences for food safety. In this research, pH-sensitive films were prepared using purple-fleshed sweet potato starch (SPS) and sweet potato peel (SPP). Two categories of the film (i) SPS and (ii) SPS/SPP, were fabricated via solvent casting technique, incorporating different concentrations of commercial purple sweet potato anthocyanin (CA) at 0%, 1%, 1.5%, and 2% (w/v) and the physicochemical, mechanical, thermal, and morphological properties of the films were investigated. The thickness, water solubility, and swelling degree of the films increased with the increment of CA, whereas there were no significant changes in the water content (WC) of the films. Water vapor permeability (WVP) was decreased for SPS films while statistically similar for SPS/SPP films. The addition of CA reduced the tensile strength (TS) and tensile modulus (TM) yet increased the elongation at break (EaB) of the films as compared to films without CA. The FTIR results confirmed the immobilization of anthocyanin into the film. In SEM images, roughness in the surfaces of the CA-associated films was observed. A reduction of thermal stability was found for the films with anthocyanin except for the SPS/SPP CA 2% film. Furthermore, the CA-associated films showed a remarkable color response when subjected to pH buffers (pH 1 to 12) and successfully monitored chicken freshness. The fastest color migration was observed in acidic conditions when the films were immersed into aqueous, acidic, low fat, and fatty food simulants. The findings of this work demonstrated that the developed pH indicator films have the potential to be implemented as smart packaging to monitor food freshness and quality for safe consumption.

Molecular dynamics (MD) simulation is a powerful tool to study the molecular level working mechanism of corrosion inhibitors in mitigating corrosion. In the past decades, MD simulation has emerged as an instrument to investigate the interactions at the interface between the inhibitor molecule and the metal surface. Combined with experimental measurement, theoretical examination from MD simulation delivers useful information on the adsorption ability and orientation of the molecule on the surface. It relates the microscopic characteristics to the macroscopic properties which enables researchers to develop high performance inhibitors. Although there has been vast growth in the number of studies that use molecular dynamic evaluation, there is still lack of comprehensive review specifically for corrosion inhibition of organic inhibitors on ferrous metal in acidic solution. Much uncertainty still exists on the approaches and steps in performing MD simulation for corrosion system. This paper reviews the basic principle of MD simulation along with methods, selection of parameters, expected result such as adsorption energy, binding energy and inhibitor orientation, and recent publications in corrosion inhibition studies.

This study was carried out to compare the antioxidant and nutritional properties of coconut (Cocos nucifera L.) sap with other natural sources of sugar such as sugar palm (Borassus flabellifer) and sugarcane (Saccharum officinarum L.). Coconut sap and juice from sugar palm and sugarcane were analyzed for proximate composition, pH and total soluble solid (TSS), color, sugar profile, vitamin profile, antioxidant properties (total phenolic contents, DPPH, FRAP, and ABTS), and mineral content. The results indicated that coconut sap possesses high DPPH (23.42%), FRAP (2.09 mM/ml), and ABTS (21.85%) compared with the juices. Coconut sap also had high vitamin C (116.19 µg/ml) and ash (0.27%) contents, especially in potassium (960.87 mg/L) and sodium (183.21 mg/L) which also indicating high content of minerals. These properties showed that coconut sap could be served as a potential healthier sugar source compared with sugar palm and sugarcane juices.