dc.contributor.author	Shaharuddin, Shahrulzaman
dc.date.accessioned	2024-06-22T09:53:42Z
dc.date.available	2024-06-22T09:53:42Z
dc.date.issued	2015
dc.description	Thesis (PhD. (Bioprocess Engineering))
dc.description.abstract	Normally, probiotic is applied in its initial form before mixed with other ingredients in pelleted animal feed. During heat-treatment in pelleting process, the viability and effective activity of the probiotic reduce significantly. This research aimed to design a thermotolerant microcapsule of immobilized probiotic Lactobacillus rhamnosus NRRL 442 using sugarcane bagasse-alginate composite as encapsulant agent. The microcapsule was produced by combination of immobilization and microencapsulation techniques via adsorption and extrusion, respectively. Pretreated sugarcane bagasses (SB) were used as probiotic carrier. Firstly, L.rhamnosus (Lr) was immobilized with the SB. Then the microcapsules of immobilized probiotic on bagasse-alginate (NaA-SB) composite were synthesized using extrusion method to provide double protection effect to the probiotic. It was found that high immobilization efficiency of L.rhamnosus (97.67% ± 0.42) can be obtained. From scanning eletron microscope (SEM) micrographs, the attachment of L.rhamnosus was observed mainly on the SB surface with almost similar structural properties as compared with the raw SB. Microencapsulation process with ratio of NaA:SB of 1:1.5 and 1:1 attained the highest efficiency (89.35% ± 0.49 and 89.35% ± 0.21, respectively). The highest cell survivability after the heat exposure was observed in the sample synthesized using 3% of NaA and NaA:SB ratio of 1:1.5 (81.30±0.30%). The recommended parameters for immobilization and microencapsulation process were 1:8 of the SB:L.rhamnosus ratio and 3% of NaA concentration with NaA:SB ratio of 1:1.5, respectively. The step of probiotic immobilization before microencapsulation significantly enhanced microencapsulation efficiency and cell survivability following heat exposure of 90 ºC for 30 seconds. SEM images after the heat exposure analysis showed the evidence of survived probiotic in bagasse-alginate microcapsule. The thermotolerance of probiotic increased with the increase of microcapsule diameter. In addition, fourier transform infrared spectroscopy spectra confirmed the improvement in functional bonding with the synergical presence of sugarcane bagasse, probiotic and alginate. Hence, the cell survivability after heat exposure was enhanced using double heat protection via microencapsulation of immobilized probiotic. Heat movement and the mechanism of heat resistance during the heat exposure were illustrated. The regression model exhibited strong correlation between effective thermal conductivity and encapsulant concentration whereby these results were in good agreement with cell survivability results. These findings demonstrated a great potential of heat resistant microcapsules for probiotic and then for inclusion as probiotic additive
dc.description.sponsorship	Faculty of Chemical Engineering
dc.identifier.uri	http://openscience.utm.my/handle/123456789/1216
dc.language.iso	en
dc.publisher	Universiti Teknologi Malaysia
dc.subject	Lactobacillus
dc.subject	Probiotics
dc.subject	Pelletizing
dc.title	Thermotolerance of lactobacillus rhamnosus NRRL 442 encapsulated in bagasse-alginate microcapsule
dc.type	Thesis
dc.type	Dataset

Thermotolerance of lactobacillus rhamnosus NRRL 442 encapsulated in bagasse-alginate microcapsule

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