Influence of the inlet air temperature on the microencapsulation of kenaf (Hibiscus cannabinus L.) seed oil.

The aim of this study was to evaluate the influence of different inlet air temperatures on the physicochemical properties and oxidative stability of microencapsulated kenaf seed oil (MKSO). Kenaf seed oil was homogenised with the wall materials at a total solid content of 30% and was spray-dried at 160, 180 or 200°C inlet air temperature. The microstructure and morphology of the microencapsulated kenaf seed oil were observed using a scanning electron microscope. The physicochemical properties, such as moisture content, water activity and particle size, of MKSO produced at different inlet air temperatures showed a significant difference (p<0.05). MKSO produced with an inlet air temperature of 160°C exhibited the highest microencapsulation efficiency (MEE, 96.46%) compared to 180°C (78.42%) and the efficiency was lowest at 200°C (58.96%). Increasing the inlet air temperature also resulted in significantly increased (p<0.05) lipid oxidation of MKSO and decreased total intrinsic phenolic content upon accelerated storage. However, all MKSO had lower lipid oxidation and higher total phenolic content than bulk (unencapsulated) oil. This study indicates that increased inlet air temperature results in larger particle size, higher lipid oxidation and lower MEE. The process of microencapsulation could protect oil from the external environment that causes lipid oxidation. Practical applications: Kenaf seed oil contains PUFA and phytosterols, which are beneficial to human health. However, the PUFA in kenaf seed oil is susceptible to lipid oxidation, which degrades its nutritional value. Microencapsulation is used to protect the kenaf seed oil from being oxidised. By knowing the influence of the inlet air temperature on the physical properties and oxidative stability of the microencapsulated kenaf seed oil, the ideal inlet air temperature can be used to produce microencapsulated kenaf seed oil, which may be incorporated into food products to supplement the bioactive compounds that are beneficial to human health

Anti–hypercholesterolemic effect of kenaf (Hibiscus cannabinus L.) seed on high–fat diet Sprague dawley rats

AbstractObjectiveTo 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.MethodsKenaf 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.ResultsAll 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.ConclusionsDKSM, 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

Development of a palm olein oil-in-water (o/w) emulsion stabilized by a whey protein isolate nanofibrils-alginate complex

An oil-in-water (o/w) emulsion is a system where the oil droplets are dispersed within a watery phase. The most important function of emulsions is their ability to incorporate lipophilic components into food matrices. Thus, it is crucial to develop an emulsion that is highly stable. This work was aimed at developing a palm olein o/w emulsion stabilized by a whey protein isolate nanofibrils-alginate complex, as well as evaluating the influence of oil load and the homogenization process (both pressure and cycle) on the characteristics of the o/w emulsions. Emulsions were analyzed for droplet size, zeta potential, viscosity, creaming stability, and morphology. The results showed that an increase in oil load led to a larger droplet size, less negative zeta potential, and emulsions that were more viscous and less stable. On the other hand, increasing homogenization pressure and the number of homogenization cycles resulted in a smaller droplet size, more negative zeta potential, and emulsions that were less viscous and more stable. Emulsions with a smaller droplet size and better stability resulted from lower oil load, high homogenization pressure and more homogenization cycles

Development and application of novel ɞ-lactoglobulin nanofibrils coacervated with alginate for encapsulation of carotenoids enriched palm olein

β-Lactoglobulin (β-lg) has the ability to form fibrils, and palm carotenoids have important biological activities affecting human health. However, carotenoids are unstable, and their insolubility in water makes them difficult to incorporate into many food matrixes. Therefore, this study addressed the development and application of β-lg nanofibril to produce palm carotenoid emulsions to improve the stability and bioavailability of these carotenoids. First, the impact of different stirring speeds on the characteristics of β-lg fibrils was investigated. The results showed that stirring significantly (p<0.05) enhanced the formation and stability of β-lg fibril. Second, a β-lg nanofibril solution was produced by a homogenization process. The results showed that increasing the homogenization pressure and cycles led to significantly decrease the fibril concentration, particle size, viscosity and turbidity. The emulsifying properties of the β-lgs were generally improved by the homogenization process. Third, different concentrations of sodium alginate (0.2-1.0% w/w) were added to a fixed concentration of β-lg nanofibrils (1.0% w/w) to form a complex. The results showed that the zeta potential decreased from a positive charge to a more negative charge (+13.7 ± 1.4 to -41.7 ± 1.2 mV). The addition of alginate resulted in an increase in the emulsifying properties of the β-lg nanofibrils. Fourth, the complex was used to produce a palm olein oil-in-water (o/w) emulsion. The results showed that increasing the oil concentration caused an increase in viscosity and particle size and reduced emulsion stability. The homogenization process was shown to produce an emulsion that with smaller particle size (29.92 ± 5.8 to 0.82 ± 0.05 μm), more negative of zeta potential (- 59.5 ± 2.0 to -67.5. ± 1.2 mV), less viscous (26.0 ± 0.7 to 11.8 ± 0.1 mPa-s) and more stable of emulsions (75.0 ± 3.5 to 91.3 ± 1.9%). Finally, the palm carotenoids were incorporated into the palm olein oil to produce β-lg nanofibrilalginate complex-stabilized palm carotenoids. The results showed minimal changes in the carotenoid content of the emulsion upon exposure to environmental stresses and storage, indicating the high stability of the emulsion. In addition, the cellular uptake of the emulsion (931.30 ± 125.50 fmol/ cell) was double compared to bulk oil (509.30 ± 37.30 fmol/ cell). The findings of this study suggest the suitability of the β-lg nanofibril-alginate complex to produce a palm carotenoid emulsion that exhibits high stability and better bioavailability

Effect of accelerated storage on microencapsulated kenaf seed oil.

In order to improve the quality and protect against degradation, kenaf (Hibiscus cannabinus L.) seed oil was microencapsulated by using spray drying. The microencapsulated kenaf seed oil (MKSO) was then stored at 65 °C for 24 days, the changes of fatty acids and bioactive compounds were examined every six days. Bulk (unencapsulated) kenaf seed oil was used as a control and was compared to the MKSO. The fatty acids and phytosterols compositions were determined by using gas chromatography, while tocopherols and phenolic acids of microencapsulated kenaf seed oil were determined by using high performance liquid chromatography. The results showed that there was a significant decrease (p < 0.05) in bioactive compounds in kenaf seed oil while the bioactive compounds in MKSO were maintained in a stable condition upon accelerated storage. Microencapsulation was shown to protect kenaf seed oil against oxidation, as well as preventing the degradation and/or loss of bioactive compounds in kenaf seed oil

Effect of total solids content in feed emulsion on the physical properties and oxidative stability of microencapsulated kenaf seed oil

Kenaf (Hibiscus cannabinus L.) seed oil has high potential to be used as edible oil. Despite the high content of polyunsaturated fatty acids, one of the major complications in commercialisation kenaf seed oil is its rapid oxidation, which leads to the production of undesirable toxic substances such as peroxides. The objective of this study was to investigate the effect of total solids content (TSC) on the oxidative stability of microencapsulated kenaf seed oil (MKSO) and to compare its oxidative stability with bulk kenaf seed oil upon accelerated storage. Microcapsules with 20%, 30% and 40% total solids content were prepared. Physical properties, such as the emulsion characteristics and microcapsules characteristics were also studied. Results showed that bulk kenaf seed oil was oxidised to a greater extent compared to the microencapsulated samples. The results showed that 40% total solids content microcapsules had the lowest peroxide value (PV), p-anisidine value (AnV), total oxidation (TOTOX) value and free fatty acid (FFA) value, which were 3.70 ± 0.83 meq O2/kg oil, 16.12 ± 0.19, 23.52 ± 1.67 and 2.54 ± 0.06%, respectively. The microencapsulation of kenaf seed oil showed protective effect against lipid oxidation

Impact of stirring speed on B-lactoglobulin fibril formation

β-Lactoglobulin (β-lg) can produce fibrils that have multi-functional properties. Impacts of different stirring speeds on characteristics of β-lg fibrils as a stable form in β-lg fibril solutions were investigated. Fibril concentration, fibril morphology, turbidity, particle size distribution, zeta potential, and rheological behavior of solutions were studied. Stirring enhanced fibril formation and stability of a fibril solution, in comparison with unstirred solutions. Increasing the stirring speed produced more turbidity and a greater distribution of particle sizes, higher viscosity values, but no differences in zeta potential values of β-lg fibril solutions. However, a high stirring speed is not feasible due to reduction of the fibril yield and changes in fibril morphology