RESULTS: Defatted kenaf seed powder yielded four DF fractions: alkali-soluble hemicellulose (146.4 g kg-1 ), calcium-bound pectin (10.3 g kg-1 ) and acid-soluble pectin (25.4 g kg-1 ) made up the soluble fibre fraction, whereas cellulose (202.2 g kg-1 ) comprised the insoluble fraction. All fractions were evaluated for their physicochemical properties. The DF fractions contained glucose, mannose, xylose and arabinose, and a small amount of uronic acid (1.2-2.7 g kg-1 ). The isolated pectin fractions had a low degree of esterification (14-30%). All the isolated DF fractions had high average molecular weights ranging from 0.3 to 4.3 × 106 g mol-1 . X-ray diffractogram analysis revealed that the fractions consisted mainly of an amorphous structure with a relative crystallinity ranging from 31.6% to 44.1%. The Fourier-transform infrared spectroscopy spectrum of kenaf seed and its DF fractions showed typical absorption of polysaccharides, with the presence of hydroxyl, carboxyl, acetyl and methyl groups. Scanning electron microscopy analysis demonstrated that the raw material with the rigid structure resulted in soluble and insoluble DF fractions with more fragile and fibrous appearances, respectively. The soluble DF demonstrated greater flowability and compressibility than the insoluble fractions.
CONCLUSION: These findings provide novel information on the DF fractions of kenaf seeds, which could be used as a potential new DF for the food industry. © 2023 Society of Chemical Industry.
RESULTS: The moisture, pH and sugar composition of all SBH samples adhered to the Malaysian Kelulut Honey Standard (MS2683:2017) but not to the International Codex Standard (CODEX) for honey. Trehalulose presence in all samples, regardless of geographical area, was predominant alongside fructose and glucose. Only hydroxymethylfurfural (HMF) content and electrical conductivity (EC) results complied with both standards. The principal component analysis biplot showed that the discrimination of SBH according to the five different areas was not feasible, indicating sample homogeneity.
CONCLUSION: The physicochemical evaluation of SBH from Peninsular Malaysia shows mainly homogeneous attributes of samples across geographical locations. These findings demonstrated that the current MS2683:2017 is relevant and accommodates all SBH of H. itama species produced in Peninsular Malaysia. Furthermore, the trehalulose range calculated in this study can be implemented as a new benchmark for the indicator of SBH honey quality standard by national and international food standard committees. © 2023 Society of Chemical Industry.