ABSTRACT
We focused on assessing the antimicrobial effects of functional yoghurts supplemented with clove and probiotics. The formulation of aqueous clove extract (ACE) incorporated with probiotic yoghurt (Streptococcus thermophilus, Lactobacillus bulgaricus, and Lactococcus lactis) was optimised in terms of aqueous clove extract concentrations (2.5-7.5% v/v), fermentation temperature (32-42 °C), and total culture concentration (1.5-4.5% v/v). pH, titratable acidity, syneresis, water holding capacity, viscosity, springiness, color difference, lactic acid bacteria viability, and the antibacterial property of 17 runs were determined as responses using Box-Behnken design. The results indicate that elevated ACE concentration leads to a significant (p < 0.05) increase in titratable acidity, antibacterial effectiveness (against K. pneumoniae and P. aeruginosa), springiness, and color profile. Conversely, an elevated fermentation temperature significantly (p < 0.05) reduces pH and L. bulgaricus viability (log CFU/mL). Additionally, there is a significant (p < 0.05) decline in S. thermophilus and L. lactis viability (log CFU/mL) as well as springiness with an increased culture concentration. The optimal conditions identified are 7.5% (v/v) ACE concentration, a fermentation temperature of 36.6 °C (37 °C), and a total culture concentration of 4.5% (v/v), resulting in a 79% desirability score. The spectra of components were mainly obtained at wavelength of 3258 cm-1, 1636 cm-1 and 1075 cm-1 in Fourier transform infrared (FTIR) spectroscopy of optimized functional yoghurt. Where, 3258 cm-1 corresponds to the stretching vibration of O-H (hydroxyl) groups, 1636 cm-1 corresponds to the C=O (carbonyl) stretching vibration, and 1075 cm-1 corresponds to the C-O (ether or alcohol) stretching vibration.
ABSTRACT
OBJECTIVE: To determine the antihypercholesterolemic effects of kenaf seed samples and compare with the commercial hypocholesterolemic drug on serum lipids profiles and malondialdehyde (MDA) level in the rat. METHODS: Kenaf seed oil (KSO), microencapsulated kenaf seed oil (MKSO), kenaf seed extract (KSE) and defatted kenaf seed meal (DKSM) were prepared and phytochemicals screening on these samples were done prior in vivo study. Phenolic compounds in KSE were quantified using high performance liquid chromatography. There were 40 (divided in eight diet groups of 5) male Sprague dawley rats adapted to normal standard diet or hypercholesterolemic diet (HD) with or without the treatment of these kenaf samples for 32 days. RESULTS: All the kenaf samples exhibited to contain most of the major phytochemicals. KSE possessed gallic acid, tannic acid, catechin, benzaldehyde, benzoic acid, syringic acid, sinapic acid, ferulic acid, naringin acid, and protocatechuic acid. The significant higher (P<0.05) serum total cholesterol, low density lipoprotein cholesterol and MDA levels in HD group without treatment than the normal control group suggested the hypercholesterolemia was induced by the incorporation of cholesterol into diet. KSE exhibited higher cholesterol-lowering properties due to the significant lower (P<0.05) in serum triglycerides, total cholesterol and MDA levels. KSE showed the highest efficiency of cholesterol-lowering activity, followed by KSO, MKSO and DKSM. CONCLUSIONS: DKSM, MKSO, KSO and KSE appeared to have comparable anti-hypercholesterolemic effect with the commercial hypocholesterolemic drug. Hence, kenaf seed could be used as an alternative natural source to replace the synthetic hypocholesterolemic drugs.