http://mfuir.mfu.ac.th:80/xmlui/handle/123456789/1084 Innovative Food Science and Technology 2026-07-25T23:20:55Z http://mfuir.mfu.ac.th:80/xmlui/handle/123456789/1821 The influence of drying methods on the quality characteristics of kai (Cladophora glomerata) powder and Its potential application in dysphagia food formulation Yonn Pwint Phyu Nattaya Konsue People with dysphagia require foods that are safe to swallow, and 3D food printing offers a promising approach for developing such texture-modified products; however, its effectiveness depends on the availability of ingredients with suitable functional and rheological properties. Kai (Cladophora glomerata), a freshwater alga traditionally consumed in Northern Thailand, is rich in protein, minerals, and bioactive compounds. However, its functional properties are strongly influenced by drying methods. This study investigated the effects of freeze-drying (FD), sun drying (SuD), and tray drying at 50°C (TD) on Kai powder properties and its potential application in 3D-printable dysphagia-friendly food formulations. In Phase I, fresh Kai was processed by FD, SuD, and TD, and the resulting powders were evaluated for proximate composition, mineral content, in vitro protein digestibility, chlorophyll and phytochemical content, antioxidant and anti-inflammatory activity, techno-functional properties, microstructure, and FTIR characteristics. TD retained the highest protein (13.95 %), chlorophyll (4.41 mg/g), flavonoid (6.60 mg QE/g), and antioxidant (FRAP: 20.86 mmol Fe²⁺/g) contents, along with the greatest absolute digestible protein yield (9.57 g/ 100 g) and exhibited potent anti-inflammatory activity at low concentrations (12.5–25 µg/mL), suppressing NF-κB-mediated inflammatory responses while strongly activating the Nrf2/HO-1 antioxidant defense pathway. Sun drying showed the highest phenolic content, DPPH activity, water holding capacity, and protein digestibility (82.55 %). FD preserved superior emulsifying properties and demonstrated anti-inflammatory activity at 100–200 µg/mL. All drying methods produced mineral-rich powders with heavy metal contents below EU safety limits. Due to its superior balance of nutritional quality, functional performance, and practical scalability, TD was selected for Phase II and formulated with xanthan gum (XG) and konjac gum (KG) using response surface methodology. Sixteen formulations were evaluated for rheological behavior, texture profile, print accuracy, syneresis, deformation, microstructure, and dysphagia-oriented texture characteristics. All formulations exhibited pseudoplastic shear-thinning behavior. Formulations with total gum between 6 % and 9 % and XG:KG ratios of approximately 1:2 to 3:1 gave the best print accuracy and passed IDDSI Level 4, Japanese Standard Regulation, and UDF Stage 4 criteria. The RSM models showed good predictive performance (R² = 0.8456–0.9750) and the predicted optimum formulation contained 5.265 % xanthan gum and 3.186 % konjac gum. Overall, the findings demonstrate that drying-induced structural modifications strongly influence the functional performance of Kai powder and highlight the potential of tray dried Kai as a functional ingredient for personalized dysphagia-friendly 3D food printing applications. Validation of the predicted optimum formulation remains to be performed to confirm its practical printing performance. Thesis (M.Sc.) -- Innovative Food Science and Technology, School of Agro-Industry. Mae Fah Luang University, 2025 2025-01-01T00:00:00Z http://mfuir.mfu.ac.th:80/xmlui/handle/123456789/1794 Effects of lactic acid fermentation on citrulline content in watermelon (Citrullus lanatus) rind Shankar Neupane Nattaya Konsue Watermelon rind, a major agricultural by-product of watermelon, is often discarded as waste despite its edibility. Fermentation in situ offers a sustainable approach to reintegrating such underutilized materials into the food value chain by enhancing preservation, safety, and bioactive compounds. This study aimed to optimize fermentation conditions to enhance L-citrulline, the predominant functional amino acid in watermelon rind with known health benefits. Natural fermentation was carried out by varying salt concentration (2%, 4%, and 6%), temperature (25, 30, 35, and 40 °C), and duration, and their effects on microbial dynamics, acidification, amino acid profile including citrulline and its metabolic flux, and other phytochemical properties were evaluated. Microbiological analysis demonstrated that 6% salt facilitated the highest lactic acid bacteria (LAB) growth, reaching peak populations across all temperatures. At 30°C, sustained LAB growth was observed with the minimum final pH (3.23±0.01), establishing it as the optimal temperature for controlled fermentation. Enterobacteriaceae, initially present at high levels (7.35–7.72 log CFU/g), became undetectable in all samples by day 5, while yeast and mold populations were suppressed within 2 to 6 days. Subsequent fermentation at 30°C for 48 h demonstrated that amino acids involved in the arginine deiminase (ADI) pathway were strongly influenced by both salt concentration and fermentation time. While low-salt conditions (2% and 4%) led to citrulline depletion through its conversion to ornithine, 6% salt inhibited subsequent citrulline metabolism, resulting in significant accumulation reaching 737.12±12.50 mg/kg at 12 hours, compared to 652.41±7.77 mg/kg in the unfermented sample. Although citrulline levels declined thereafter, they remained significantly higher than the initial concentration throughout fermentation. These findings indicate that fermentation for 12 h at 6% salt concentration represents the optimal condition for enhancing citrulline content. Total phenolic content (TPC) increased significantly across all treatments, with the 2% salt sample showing the highest relative increment (71.59%). DPPH radical scavenging activity more than doubled after 48 h, reaching 1.189–1.281 mg TE/g FW. Among free amino acids, glutamic acid and aspartic acid were more abundant at lower salt levels, suggesting greater umami character, while proline, threonine, histidine, lysine, and glutamine were elevated at higher salt concentrations. In case of color parameters, 6% salt better preserved rind lightness and yellowness, although greenness declined across treatments due to acid-induced chlorophyll degradation. These findings demonstrate that higher salt concentration not only promotes higher LAB counts but also drives citrulline overproduction, particularly at short fermentation durations. These findings support the valorization of watermelon rind by defining optimized fermentation conditions for citrulline enhancement, contributing to both agricultural waste reduction and the development of functional fermented products. Thesis (M.Sc.) -- Innovative Food Science and Technology, School of Agro-Industry. Mae Fah Luang University, 2025 2025-01-01T00:00:00Z http://mfuir.mfu.ac.th:80/xmlui/handle/123456789/1790 Utilization of sacha inchi press cake in the production of plant-based meat alternatives Janet Wamuni Njoroge Natthawuddhi Donlao This study evaluated the valorization of Sacha inchi press cake (SP), an oilseed by-product, to produce texturized vegetable protein (TVP) using single-screw extrusion. Steam pretreatment effectively reduced tannin content by 23.6% and saponin contents by 25% ,enhancing palatability of the Pretreated SP, referred to as Sacha inchi press cake meal (SPM), was blended with pea protein isolate (PPI) at SPM:PPI (w/w) ratios to produce five formulations: Control (0:100), TA (10:90), TB (35:65), TC (70:30), and TD (100:0). Increasing SPM incorporation in TVP formulations significantly altered color parameters, as evidenced by decreased lightness and increased redness and yellowness, thereby imparting a more meat-like appearance; however, elevated SPM levels were associated with a progressive decline in textural integrity. Among formulations, TA displayed a more compact and continuous microstructure with reduced pore formation and favorable textural properties comparable to commercial TVP (COM). Based on these characteristics, TA was selected for further analysis, showing high protein content (69.42%, d.b.), a balanced essential amino acid profile, and a predominance of oleic and linoleic acids without detectable trans fats. When incorporated into a burger patty, TA showed higher protein content (45.43%, d.b.) and fat retention while maintaining comparable cooking performance to commercial TVP based burger patty. Despite instrumental differences in color and texture, sensory evaluation (n=30) using a 9 -point hedonic scale showed no significant differences (p > 0.05) in appearance, aroma, taste, texture, or overall acceptance between TA (7.14), COM (6.77), and minced chicken burgers (7.27). Consumer perception data further indicated that the SPM-based burger was associated with health, modernity, and environmental sustainability, with acceptance independent of food neophilia. These findings demonstrate the technological feasibility, nutritional value, and sensory competitiveness of upcycled Sacha inchi press meal as a sustainable ingredient for plant-based meat analogues, although further refinement of structural anisotropy and texture through advanced extrusion strategies may enhance meat-like fidelity. Thesis (M.Sc.) -- Innovative Food Science and Technology, School of Agro-Industry. Mae Fah Luang University, 2025 2025-01-01T00:00:00Z 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 2025-01-01T00:00:00Z