The effect of oven drying at 50ᵒC ± 1ᵒC for 9 hour, 70ᵒC ± 1ᵒC for 5 hour and freeze drying on retention of chlorophyll, riboflavin, niacin, ascorbic acid and carotenoids in herbal preparation consisting of 8 medicinal plants was evaluated. The medicinal plants selected were leaves of Apium graveolens (saderi), Averrhoa bilimbi (belimbing buluh), Centella asiatica (pegaga), Mentha arvensis (pudina), Psidium guajava (jambu batu), Sauropus androgynous (cekor manis), Solanum nigrum (terung meranti) and Polygonum minus (kesum ). Results revealed that both type and conditions of the drying treatments affected retention of all phytochemicals analysed. Herbal preparation developed using oven drying was found to have inferior phytochemicals content compared to that obtained by freeze dryer. Nevertheless, the herbal preparation developed using all treatments still retain appreciable amount of phytochemicals studied, especially carotenoids, ascorbic acid, niacin and riboflavin and thus have potential for commercial purposes.
Pitaya peel (Hylocereus polyrhizus), which consists approximately 22% of the whole fruit weight, is discarded during processing. Physico-chemical properties of the discarded pitaya peel were determined in
order to evaluate its potential for recovery of any value-added materials. The moisture content of the peel was approximately 92.7% and it was low in total soluble solids, protein, ash and fat content. Betacyanin pigment (150.46 ± 2.19 mg/100 g) and pectin (10.8%) were high in the peel. Glucose, maltose and fructose were detected in the peel but not sucrose and galactose. The peel also had very high insoluble and soluble dietary fibre which had exhibited a good ratio of insoluble dietary fibre to soluble dietary fibre (3.8: 1.0).
To examine whether earthworms of Eisenia fetida, Lumbricus rubellus and Eudrilus eugeniae extracts have elastase, tyrosinase and matrix metalloproteinase-1 (MMP-1) inhibitory activity.
Oscillatory and steady shear rheology of gellan (G) and dextran (D) solution individually, and in blends (G/D ratio 1:1, 1:2, and 1:3 w/v) with a total hydrocolloid concentration of 3 % (w/v) were studied at 25 °C. Individually, 1.5 % dextran and 1.5 % gellan in solution exhibited Newtonian and non-Newtonian behavior, respectively. A blend of equal proportion of dextran and gellan (G/D = 1:1) exhibits a distinct gel point (G' = G″), and further addition of dextran in the blend (G/D = 1:2 and 1:3) resulted predominating liquid-like (G″ > G') behavior. A plot of G' vs G″ distinctly showed the gradual transition of the blend. Shear stress (τ)-shear rate ([Formula: see text]) data fitted well the Herschel-Bulkley model. The G/D blend exhibited shear thinning behavior with flow behavior index less than unity. The Cox-Merz rule did not fit well for the complex shear viscosity (η*) and apparent viscosity (η) of the blend.
A detailed procedure for estimating uncertainty according to the Laboratory of Government Chemists/Valid Analytical Measurement (LGC/VAM) protocol for determination of 18 amino acids in gelatin is proposed. The expanded uncertainty was estimated using mainly the method validation data (precision and trueness). Other sources of uncertainties were contributed by components in standard preparation measurements. The method scope covered a single matrix (gelatin) under a wide range of analyte concentrations. The uncertainty of method precision, μ(P) was 0.0237-0.1128pmolμl(-1) in which hydroxyproline and histidine represented the lowest and highest values of uncertainties, respectively. Proline and phenylalanine represented the lowest and highest uncertainties value for method recovery, μ(R) that was estimated within 0.0064-0.0995pmolμl(-1). The uncertainties from other sources, μ(Std) were 0.0325, 0.0428 and 0.0413pmolμl(-1) that were contributed by hydroxyproline, other amino acids and cystine, respectively. Hydroxyproline and phenylalanine represented the lowest and highest values of expanded uncertainty, U(y) that were determined at 0.0949 and 0.2473pmolμl(-1), respectively. The data were accurately defined and fulfill the technical requirements of ISO 17025:2005.
Ice cream mixes containing 33.4% total solids including 10% fat, 11.1% milk solid-non fat (MSNF), 12% sugar, 0.35% commercial blend of emulsifier/ stabiliser and water were produced. The blending of PO with AMF were conducted at three different ratios 30: 70, 50: 50 and 70: 30, respectively. The experimental ice cream mixes were compared with a control ice cream mix prepared from AMF. The flow properties were measured after ageing at 0, 1, 1.5, 2 and 24 h and determined using a controlled stress rheometer (Haake RS 100). The Power Law and Casson equation was employed to estimate the yield stress of an ice cream mixes. The regression coefficients (r) was represented well by the Casson model (r > 0.99) for all the samples, indicating goodness of fit. The profiles of the consistency coefficients (K(c)) were quite similar for all experimental samples, which could be attributed to the fact that all the samples exhibited similar viscoelastic behaviour. The flow behaviour index (n) of an ice cream mix prepared from PO and their blends with AMF were less then 1.0 (range 0.04-0.08) indicating that they were psuedoplastic fluid. The eta(o) at shear rate 20(-1) indicated higher degree of viscosity in AMF.