Pusat Pengajian Teknologi Industri - Tesis

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Fermentation Of Dehydrated Fruit Juices By Lactobacillus Spp. With Prebiotic Supplementation As Non-Dairy Functional Beverages
(2025-03)
Sa'Aid, Nurhazwani
Fruit juice, derived from edible fruit flesh and unfermented, can be enhanced by fermenting with lactic acid bacteria (gras) to improve health benefits. This study evaluated lactic acid production, growth profile, and cell viability of different lactobacillus spp. In fruit juice fermentation and examined the effects of prebiotics on functional beverage development. In this study, five lactobacillus spp., namely lacticaseibacillus paracasei, lactiplantibacillus plantarum, l. Acidophilus, l. Rhamnosus, and limosilactobacillus reuteri were utilized to ferment five different fruit juices; mango, pineapple, dragon fruit, cranberry and mixed berry juices. Among them, l. Plantarum demonstrated superior growth and viability with comparable lactic acid production and was selected for further study. The impact of inulin and galacto-oligosaccharides (gos) on fermentation was also assessed over 72 hours. Inulin significantly enhanced l. Plantarum growth, especially at 12 hours in mango juice (1.32 ± 0.014) and 24 hours in pineapple juice (0.68 ± 0.003). It also increased lactic acid production, reaching 10.22 ± 0.004 g/l in mango juice compared to 8.66 ± 0.007 g/l in the control.
Preservative Effects Of Medium-Chain Dicarboxylic Acids On Microbial Control And Quality Of Beef And Salmon During Refrigerated Storage
(2025-03)
Liao, Zhengrui
This study explores the potential of glutaric acid (gla), succinic acid (sua), and azelaic acid (aza) as natural preservatives for meat products, highlighting their physicochemical stability and antimicrobial properties. Phase 1 evaluated the antimicrobial (microdilution broth method) and in vitro antioxidant activities (dpph free radical scavenging, ferric reducing antioxidant power, and nitrite scavenging assays) of individual medium-chain dicarboxylic acids (mcdas), selecting the most effective concentrations for beef preservation. Although their antioxidant properties were less than 50% of ascorbic acid (asa), they demonstrated strong bacteriostatic effects, with minimal inhibitory concentration (mic) and minimum bactericidal concentration (mbc) values ranging from 500–2,000 μg/ml against listeria monocytogenes, staphylococcus aureus, enterococcus faecalis, pseudomonas aeruginosa, salmonella enterica, and escherichia coli. In beef models, higher mcda concentrations (2,000 μg/ml and 1,456 μg/g) helped maintain colour, ph, and moisture while reducing spoilage indicators such as total volatile base nitrogen (tvb-n) (8–20 mg/100 g decrease) and microbial counts. Aza was the most effective, outperforming sodium bisulphite (sob). Phase 2 assessed the combined antimicrobial effects of gla, aza, and sua using checkerboard tests, leading to the selection of optimal ratios (gla-aza 2:1, gla-sua 1:1, and aza-sua 2:1, with fractional inhibitory concentration (σfic) values of 0.039–0.5) for beef preservation.
Enhancement Of Emulsifying Properties Of Nanocellulose From Defatted Rice Bran Through Ultrasonic-Assisted Enzymatic Treatment
(2025-07)
Ilias, Nurul Najihah
Defatted rice bran (DRB) is an agricultural waste that has notable potential in the food industry. It is also considered an excellent source of bio-based cellulosic nanofibres due to its high cellulose content. The use of toxic materials in the extraction of cellulosic nanofibres can affect both consumers and the environment. This study investigates the innovative use of an environmentally friendly method that is the ultrasonic-assisted enzymatic treatment, to isolate a type of lignocellulosic nanofibres (LCNF) from defatted rice bran (DRB), named rice bran nanofibres (RBN), as potent emulsifiers for stabilizing Pickering emulsions.
Production Of Postbiotic By Lactic Acid Bacteria Through Fermentation Process As Potential Antidiabetic Agent
(2025-03)
Shunmugham, Thavan Raj
In response to the notable adverse health effects associated with the use of chemically synthesized antidiabetic drugs for individuals with diabetes, a comprehensive investigation was undertaken to explore the potential of postbiotic compounds produced by lactic acid bacteria (lab) as novel antidiabetic agents, with a particular focus on their inhibitory effects compared to acarbose. Seven lab strains were cultured to obtain supernatants and heat-killed cell (hkc) which was exposed to 80℃, which were subsequently evaluated for their inhibitory activities against α-amylase and α-glucosidase enzymes. The supernatant from lactobacillus acidophilus tp7 culture exhibited the most significant α-amylase inhibitory activity, with a percentage of 79.01 ± 1.35%, while hkc of lactococcus lactis c22 displayed an inhibition percentage of 58.17 ± 3.08%. For α-glucosidase inhibition, limosilactobacillus reuteri bm5 showed the highest inhibition percentage in both the supernatant and hkc, with percentages of 68.08 ± 0.03% and 67.78 ± 1.18%, respectively. Further fractionation of exopolysaccharide (eps), small molecules, and proteins was carried out, revealing that the crude eps extracted from l. Acidophilus’s supernatant exhibited the most remarkable inhibitory effects, with 95.90% inhibition in the α-amylase test and 75.51% inhibition in the α-glucosidase test, surpassing the other fractionated components
Bioremediation Of Refinery Oil Sludge With Food Waste Digestate As Feedstock
(2025-02)
Adnan, Muhammad Syahmi Najmi Mat
This study was to assess the bioremediation potential of food waste digestate (fwd) for treating refinery oil sludge (os), addressing significant environmental and waste management challenges. Os is a byproduct of petroleum refining poses an environmental risk due to its complex hydrocarbon and persistent pollutants. Recent petroleum oil sludge treatment methods approach possesses fundamental drawbacks in terms of operating expenses, effectiveness, and produce secondary pollutants. Food waste (fw) is a global crisis as it is disposed of through incineration and landfills that produce greenhouse gas (ghg) pollution, methane emission from landfill decomposition, and water pollution affecting social, environmental, and economic issues. This study aims to investigate the potential of using fwd as valuable resources for co-digestion with os by identifying the microbial morphology in fwd, assessing the effectiveness in enhancing the total petroleum hydrocarbon (tph) degradation rates, and examining its potential as a soil amendment via seed germination test.

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