DSpace Community: Department of Food Technology

USE OF RSM TO OPTIMIZE DRYING TEMPERATURE AND LENGTH OF LEMONGRASS (Cymbopogan Citratus) AND ENHANCE SENSORY PROFILE OF GREEN TEA (Camellia Sinensis)

Thu, 01 Jan 2026 00:00:00 GMT

Title: USE OF RSM TO OPTIMIZE DRYING TEMPERATURE AND LENGTH OF LEMONGRASS (Cymbopogan Citratus) AND ENHANCE SENSORY PROFILE OF GREEN TEA (Camellia Sinensis) Authors: Gyawali, Bipana Abstract: The objective of this study was to optimize the drying temperature and length of lemongrass (Cymbopogon citratus) with respect to phytochemical content and antioxidant activity, and to evaluate its suitability for incorporation into green tea (Camellia sinensis) as a functional beverage. Fresh lemongrass leaves were cut into different lengths (1, 3, and 5 cm) and dried at varying temperatures (30°C, 45°C, and 60°C). Response Surface Methodology (RSM) using a Central Composite Design was applied to assess the combined effect of drying temperature and length on total phenolic content, total flavonoid content, tannin content, and DPPH radical scavenging activity. The optimized dried lemongrass was blended with green tea at different ratios, and the resulting tea samples were evaluated for sensory attributes using a nine-point hedonic scale. The results showed that both drying temperature and length significantly influenced the phytochemical composition and DPPH radical scavenging activity of lemongrass. The optimum condition was identified as drying lemongrass at 47.5°C with a length of 3.8cm, yielding the highest DPPH radical scavenging activity (79.42 ± 0.18%) along with elevated flavonoid (22.56 ± 0.92 mg QE/100 g), polyphenol (17.9 ± 0.03 mg GAE/100 g), and tannin contents (0.40± 0.02 mg/100 g). Higher drying temperatures and larger length led to significant losses of bioactive compounds (p < 0.05). Sensory evaluation revealed that green tea incorporated with optimally dried lemongrass showed superior acceptability compared to the control (6±0.408). The study concludes that optimized drying conditions effectively preserve the functional properties of lemongrass and enhance the sensory quality of green tea. Description: A dissertation submitted to the Department of Food Technology, Central Campus of Technology, Tribhuvan University, in partial fulfillment of the requirements for the degree of B. Tech in Food Technology

Study on Formulation, Quality Evaluation and Storage Stability of Agar Based Dragon Fruit Jelly Incorporated with Stinging Nettle

Mon, 01 Dec 2025 00:00:00 GMT

Title: Study on Formulation, Quality Evaluation and Storage Stability of Agar Based Dragon Fruit Jelly Incorporated with Stinging Nettle Authors: Oli, Krishala Abstract: The main aim of this study was to optimize the preparation of jelly made from dragon fruit juice and stinging nettle extract and to evaluate its storage stability at room temperature and refrigeration temperature. Dragon fruit and stinging nettle were purchased from the local market in Dharan, and juice was obtained through the following process. Fully ripened dragon fruits were washed, peeled, and sliced. The flesh was then cooked with water until it softened and then strained through muslin cloth to extract the juice, whereas Fresh nettle leaves were washed, blanched at 90 °C, dried at 50 °C to constant weight, ground into powder, extracted with hot distilled water for 30 min, and filtered through Whatman No. 1 to obtain the nettle extract. Seven different samples of different proportion of dragon fruit juice and stinging nettle extract were taken and coded as A (67: 33), B (63:37), C (75: 25), D (100:0) which is control, E (83:17), F (50: 50) and G (88: 12). The sugar, citric acid and Agar agar was added in the amount of 130g, 0.5% and 2% respectively. Sensory attributes of the jelly were evaluated using a nine-point Hedonic scale rating test to identify the best product. Sample C was the best and was used for further analysis at two different temperatures: room temperature (27±3°C) and refrigeration (7±1°C). The effect of storage time on physicochemical and microbial properties was evaluated. The jelly was filled in pre-sterilized glass bottles, capped, and covered with aluminium foil and stored at two temperatures as room and refrigeration, for a period of 40 days, and analysed at intervals of 10 days for chemical and microbiological changes. Physicochemical analysis of the optimized product revealed TSS of 67°Bx, pH of 3.1, acidity of 0.56% and notable antioxidant activity 73.48%. During 40 days of storage, TSS, acidity, reducing sugar, and microbial counts gradually increased, whereas vitamin C, pH, moisture, and non- reducing sugars decreased. Even with these changes, the jelly remained microbiologically safe and acceptable without using chemical preservatives. The incorporation of stinging nettle enhanced the phytochemical profile of the jelly, offering a novel, shelf-stable confectionery product with improved nutritional and functional properties. This research also shows how underutilized crops can be turned into valuable food products, while supporting the growing consumer interest in natural and health-promoting foods. Description: A dissertation submitted to the Department of Food Technology, Central Campus of Technology, Tribhuvan University, in partial fulfilment of the requirements for the degree of B. Tech. in Food Technology

VALORIZATION OF JAND RESIDUE IN MUFFIN PREPARATION

Mon, 23 Feb 2026 00:00:00 GMT

Title: VALORIZATION OF JAND RESIDUE IN MUFFIN PREPARATION Authors: Regmi, Shreeka Abstract: Millets are small, nutrient-rich cereal grains known for their drought tolerance, short growing period, and health benefits, making them a sustainable alternative to conventional cereals. The purpose of this study was to valorize fermented millet residues, a by-product of traditional millet-based alcoholic beverage production, by incorporating them into functional muffins and evaluating their physicochemical, nutritional, and sensory qualities. The residues were dried, milled, and partially substituted with wheat flour. A simple lattice design using Design Expert version 13 generated six muffin formulations with 0%, 40%, 50%, 60%, 70%, and 80% substitution levels, coded as A, B, C, D, E, and F, respectively. Proximate analysis was done for wheat flour, finger millet flour, and fermented millet residue flour. Prepared muffin samples were subjected to sensory evaluation, and the results were statistically analyzed using one-way ANOVA at a 5% significance level. Muffins prepared from each formulation were evaluated for physical properties and sensory characteristics. The results showed that fermented millet residue flour had higher protein, crude fiber, ash, calcium, iron, antioxidant activity, and total phenolic content compared to wheat flour. Higher substitution levels resulted in decreases in muffin weight, volume, and specific loaf volume. Sensory evaluation showed that the 40% substituted muffin (Sample B) was significantly superior among the substituted samples and was comparable to the control in taste, aroma, aftertaste, and overall acceptability. Chemical analysis indicated that the 40% fermented millet residue flour substituted muffin had higher protein, crude fiber, ash, calcium, iron, total phenolic compound, and antioxidant activity than the control muffin. Based on sensory and nutritional evaluation, the 40% fermented millet residue flour substituted muffin was selected as the best formulation. Microbiological analysis confirmed that the selected formulation remained acceptable for up to six days at room temperature in LDPE packaging of 50 μm, with no detection of coliforms, yeast, mold, or total viable count, indicating product safety without the use of artificial preservatives. This study demonstrates a sustainable approach to by-product valorization, converting fermented millet residues into nutrient rich functional bakery products, thereby contributing to waste reduction and enhanced food security. Description: This dissertation submitted to the Department of Food Technology, Central Campus of Technology, Tribhuvan University, in partial fulfillment of the requirements for the degree of B. Tech in Food Technology

EFFECT OF INCORPORTION OF CARROT FLOUR ON THE QUALITY OF BISCUITS

Mon, 11 May 2026 00:00:00 GMT

Title: EFFECT OF INCORPORTION OF CARROT FLOUR ON THE QUALITY OF BISCUITS Authors: Shahsankhar, Bhuwan Abstract: This study was carried out to studied the effect of incorporating carrot flour into wheat flour biscuits with the aim of improving their nutritional quality and functional value. The main objective of this study was to develop biscuits by incorporating carrot flour at different substitution levels. The study also aimed to determine the proximate composition of the developed carrot flour biscuits and to analyze the chemical composition of the most preferred biscuit formulation. Fresh carrots were washed, peeled, sliced, and subjected to hot water blanching using 0.2% potassium metabisulphite with 1% tables salt followed by blanching at 95°C for 3 minutes. The blanched slices were cabinet dried at 50°C for 16 hours and ground into fine powder. Biscuit formulations were developed by incorporating carrot flour at different substitution levels (5%,10%,15%,20%). Standard analytical methods were used for chemical analysis, while sensory evaluation was conducted by a panel of semi-trained panelists. The incorporation of carrot flour significantly improved the nutritional composition of the biscuits, particularly in terms of crude fiber, ash content, and β-carotene, while maintaining acceptable levels of other nutrients. Physical quality analysis showed that the diameter, thickness, and spread ratio of biscuits changed with the addition of carrot flour, showing its effect on dough behavior during baking. Sensory evaluation indicated that biscuits with 5% carrot flour were the most preferred for appearance, taste, texture, flavor, and overall acceptability. However, higher levels of carrot flour slightly reduced sensory scores due to stronger color and flavor. Statistical analysis using one-way ANOVA confirmed that the 5% carrot flour formulation was significantly superior (p < 0.05) among the tested samples. The study concluded that carrot flour can be successfully incorporated into biscuits up to a 5% level to enhance their nutritional and functional properties without adversely affecting consumer acceptance. Therefore, the use of carrot flour is strongly recommended for the food industry as a cost-effective and natural ingredient for the development of valueadded, health-promoting biscuit products. Description: A dissertation submitted to the Department of Food Technology, Central Campus of Technology, Tribhuvan University, in partial fulfilment of the requirements for the degree of B. Tech. in Food Technology