http://mfuir.mfu.ac.th:80/xmlui/handle/123456789/1084 Innovative Food Science and Technology Thu, 04 Jun 2026 20:39:07 GMT 2026-06-04T20:39:07Z http://mfuir.mfu.ac.th:80/xmlui/handle/123456789/1764 Thermomechanical treatment to enhance protein functionality of sacha inchi press cake Piyawan Phonphimai Natthawuddhi Donlao Sacha inchi oil residue/press cake (SP) is a protein-rich by-product of oil extraction with strong potential as a sustainable plant-based ingredient. However, its utilization in food applications is limited by restricted protein accessibility, the presence of antinutritional factors, suboptimal techno-functional properties, and undesirable sensory attributes such as bitterness and astringency. This thesis aimed to enhance the protein content and overall functionality of Sacha inchi press cake through cyclone-based dry fractionation and thermal–mechanical processing, and to elucidate the relationships between production yield, protein recovery, structural characteristics, functionality, digestibility, and application performance. In the first part of the study, cyclone-based dry fractionation following grinding and sieving (≤250 µm) was applied, yielding four fractions (F1–F4). These fractions were characterized in terms of physicochemical composition, nutritional quality, amino acid profile, bioactive compounds, and techno-functional properties. Protein enrichment was modest, increasing from 53.06% in the starting material (SP) to 56.62% in fraction F3 and 57.12% in fraction F4. Fraction F3 exhibited the highest yield (32.56%), whereas F4 showed a substantially lower yield (8.91%). Protein solubility was strongly pH-dependent, ranging from 19.96% at pH 2 to 95.76% at pH 12. Functional properties varied among fractions: F3 showed a reduction in foaming capacity (from 11.38% to 3.95%) but improved foam stability (from 88.89% to 96.83%). Emulsifying activity and stability slightly decreased (from 87.70% and 78.87% to 76.52% and 70.09%, respectively), while gelation properties improved, as indicated by a decrease in the least gelation concentration from 18% to 10%. Bioactive compound content remained largely unchanged, with total phenolic content ranging from 28.31 to 29.14 mg GAE/g and ferric reducing antioxidant power increasing from 64.04 to 79.94 µmol FeSO₄/g. The low amino acid score (0.04) indicated limited protein quality. Overall, dry fractionation resulted in only minor improvements, highlighting trade-offs between yield, protein enrichment, and functionality, and underscoring the need for complementary processing strategies. In the second part of the study, the effectiveness of autoclaving (AC) followed by colloid milling (CL) was investigated as an integrated thermal–mechanical approach to improve the physicochemical, functional, nutritional, and sensory properties of SP. The SP was autoclaved at 121 °C and subsequently subjected to colloid milling, after which the resulting materials were evaluated using the same analytical framework as in Part 1, along with application testing in cracker formulations. This combined processing significantly reduced bulk density from 0.65 to 0.25 g/cm³ and increased protein solubility at pH 2 from 19.29 to 31.79 mg/g. Water- and oil-holding capacities increased from 3.81 to 4.89 g/g and from 6.67 to 9.01 g/g, respectively, while emulsifying activity improved from 50.0% to 62.5%. In vitro gastrointestinal digestion demonstrated higher protein solubility for colloid-milled samples during both the gastric (9.34 mg/g) and intestinal (11.02 mg/g) phases compared with autoclaved samples. Amino acid analysis revealed a well-balanced essential amino acid profile, with an essential amino acid index of 108 and a predicted biological value of 106. Crackers formulated with cassava starch and autoclaved–colloid-milled press cake at a 90:10 cassava starch press cake ratio achieved the highest overall sensory acceptability score (8.62). Overall, these findings demonstrate that while cyclone-based dry fractionation alone provides limited improvements, the combination of autoclaving and colloid milling is an effective strategy for valorizing SP into a functional plant protein ingredient with enhanced nutritional quality, techno-functional performance, digestibility, and sensory acceptability, supporting its potential application in sustainable food systems. Thesis (M.Sc.) -- Innovative Food Science and Technology, School of Agro-Industry. Mae Fah Luang University, 2025 Wed, 01 Jan 2025 00:00:00 GMT http://mfuir.mfu.ac.th:80/xmlui/handle/123456789/1764 2025-01-01T00:00:00Z http://mfuir.mfu.ac.th:80/xmlui/handle/123456789/1102 Optimization of microwave-assisted extraction of bioactive compounds from different varieties of coffee pulp Mengistu Fiseha Mekonnen Nattaya Konsue Coffee, one of the most widely consumed beverages globally, generates large amounts of coffee pulp waste during processing. This Pulp, rich in bioactive compounds such as polyphenols, flavonoids, and sugars, presents an opportunity for valorization. This study aimed to optimize Microwave-Assisted Extraction (MAE) conditions for bioactive compounds from Geisha and Bourbon coffee pulp varieties using Response Surface Methodology (RSM). Microwave power (500–900 Watt), extraction time (45–80 min), and sample-to-solvent ratios (1:1 to 1:10 g/mL) were varied to evaluate their effects on extraction yield, total phenolic content (TPC), antioxidant activity (DPPH assay), and sugar content (fructose and galactose). The optimized conditions for microwave-assisted extraction (MAE) were 708.7 W for 72.3 min for the Geisha variety and 699.3 W for 71.05 min for the Bourbon variety, both utilizing a solvent-to-sample ratio of 10:1 (mL/g). Under these conditions, Geisha yielded 12.66%, with a total phenolic content (TPC) of 25.36 mg GAE/g, DPPH radical scavenging activity of 6.43 mg TE/g, fructose content of 6.65%, and galactose content of 1.46%. Bourbon yielded 10.74%, with a TPC of 23.57 mg GAE/g, DPPH activity of 6.18 mg TE/g, fructose content of 7.02%, and galactose content of 1.69%. These optimized MAE conditions for each variety were applied prior to comprehensive chemical characterization. Antioxidant activities, including ABTS and FRAP assays, as well as TPC and DPPH values, were subsequently evaluated and compared to results obtained using conventional hot water extraction methods. MAE significantly enhanced antioxidant compound recovery from coffee pulp compared to conventional extraction. TPC increased from 21.3 mg GAE/g to 25.36 mg GAE/g in Geisha and from 22.5 mg GAE/g to 24.50 mg GAE/g in Bourbon. DPPH rose from 3.16 mg TE/g to 7.51 mg TE/g in Geisha and from 3.61 mg TE/g to 7.56 mg TE/g in Bourbon. ABTS values improved from 21.25 mg TE/g to 33.78 mg TE/g in Geisha and from 20.89 mg TE/g to 32.43 mg TE/g in Bourbon. FRAP values increased from 2.44 mg TE/g to 4.56 mg TE/g in Geisha and from 2.32 mg TE/g to 4.12 mg TE/g in Bourbon. Mass spectrometry revealed a richer phenolic profile in MAE extracts, including flavonoids such as hibiscetin and alkaloids such as caffeine and trigonelline. Enzyme inhibition assays showed strong α-amylase (90%) and α-glucosidase (IC₅₀ = 2.8 mg/mL) inhibition in Geisha MAE extracts. Overall, MAE proved to be a rapid, eco-friendly method for extracting valuable bioactive from coffee pulp, with promising applications in functional foods, nutraceuticals, and sustainable waste utilization. Thesis (M.Sc.) -- Innovative Food Science and Technology, School of Agro-Industry. Mae Fah Luang University, 2025 Wed, 01 Jan 2025 00:00:00 GMT http://mfuir.mfu.ac.th:80/xmlui/handle/123456789/1102 2025-01-01T00:00:00Z http://mfuir.mfu.ac.th:80/xmlui/handle/123456789/1093 Development of chitosan nanoencapsulated clove essential oil and Its antifungal efficacy against Aspergillus niger Ahmed Abdou Said Abdelmoaty Abdelwahed Suttiporn Pinijsuwan This study focused on the development and characterization of chitosan nanoencapsulated clove essential oil (CEO-CSNPs) and its antifungal efficacy against Aspergillus niger, a common spoilage fungus. A preliminary screening was conducted to evaluate the antifungal activity of three plant essential oils, clove, cinnamon, and lemongrass using the disc diffusion method. Clove essential oil exhibited the highest inhibition zone (50.20 ± 0.51 mm), and was therefore selected for nanoencapsulation using the ionic gelation method with sodium tripolyphosphate (TPP) as the cross-linking agent. The CEO-CSNPs were characterized using Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Thermogravimetric Analysis (TGA), and Energy Dispersive X-ray Spectroscopy (EDS). These techniques confirmed the formation of spherical nanoparticles and the successful encapsulation of clove essential oil, as indicated by the presence of its characteristic functional groups within the chitosan matrix. Agar diffusion assays against Aspergillus niger demonstrated a concentration-dependent increase in antifungal activity of clove essential oil (CEO), with inhibition zones increasing by approximately 186% as the CEO concentration was raised from 5% to 100%. A similar trend was observed for nanoencapsulated CEO (CEO-CSNPs), where increasing the CEO-to-chitosan (CS) ratio from 1:1 to 1:2 resulted in an approximately 165% increase in the diameter of inhibition zones. These findings indicate that chitosan-based nanoencapsulation not only preserves but also enhances the antifungal efficacy of CEO. This encapsulation strategy offers a potential for the development of bio-based antifungal agents applicable in food preservation and shelf-life extension. supporting its potential application as a natural antifungal agent for food preservation and shelf-life extension. Thesis (M.Sc.) -- Innovative Food Science and Technology, School of Agro-Industry. Mae Fah Luang University, 2025 Wed, 01 Jan 2025 00:00:00 GMT http://mfuir.mfu.ac.th:80/xmlui/handle/123456789/1093 2025-01-01T00:00:00Z