Influence of Nickel Coating on Flexural and Dynamic Behaviour of Aluminium

AbstractElectroless deposition is an autocatalytic chemical technique to deposit a layer of metal on a thin work piece in the presence of a reducing agent. In this work the changing structure of nickel deposits on aluminum and its alloys at the early stage of electroless nickel deposition using sodium hypophosphite ion as a reducing agent has been studied. The influences of nickel coating on flexural and dynamic behaviour of aluminium are investigated using experimental and numerical methods. Three-point bending tests are performed on coated & uncoated aluminium. The natural frequency of coated specimen and uncoated specimen has been studied. The nickel coating increases the natural frequency in aluminium. Experimental results are compared with finite element Analysis

Influence of Prolonged Salting on the Physicochemical Properties of Duck Egg White

ABSTRACT Salted duck eggs are unique among the important authentic foods of Thailand. They are mainly produced in Chaiya district, Surat Thani province, in the southern part of Thailand. The egg whites of salted duck eggs are normally unusable due to heavily salty taste upon prolonged storage. The present study was aimed to examine the foaming characteristics of egg white after being cured for a prolonged period (30 days). At 5-day intervals the egg whites were measured for salt, moisture, water activity, hydrophobicity, pH, zeta potential, particle size, SH groups, surface tension and foaming properties (index of whipping, foam durability, specific density, overrun, air phase and yield stress). The results showed that prolonged curing significantly affected egg white and its foam. Salt content, hydrophobicity, particle size, and exposed SH groups gradually increased with storage period. On the other hand, moisture, water activity, pH, zeta potential, surface tension and total SH groups decreased continuously throughout the storage. In addition, foaming properties slightly declined due to accumulation of salt content with extended storage. Conversely, the yield stress - an important indicator of foam quality - increased from 32.33 to 70.55 % during storage. Overall, the egg whites could possibly serve as a key and/or a substitute ingredient in foam-based food products

Changes in quality and enzymes of Longkong (Aglaia dookkoo Griff.) fruit during storages as affected by maturation, package and methyl jasmonate treatment

Thesis (Ph.D. (Food Science and Technology))--Prince of Songkla University, 201

Effect of methyl jasmonate on physiological and biochemical quality changes of longkong fruit under low temperature storage

Introduction. Longkong (Aglaia dookkoo Griff.) fruit is a non-climacteric tropical fruit and grows widely in the South-East Asia. It has a unique taste and nutritional properties that make it more valuable to export. However, longkong exhibits a shorter shelf life at ambient (25 °C for 3−5 days) and low temperature (13 °C for 10 days) storage. Therefore, there is an urgent need to extend its shelf life and marketability by using an inexpensive and proficient technique. Materials and methods. Methyl jasmonate (MeJA) treatments with different concentrations (10, 20 and 30 μMol L-1) were used to control physiological and biochemical quality changes of longkong fruit stored at 13 °C and 85% relative humidity. Fruit with no MeJA treatment served as control. The physiological and biochemical quality analyses were carried out at every four days of the interval. Results and discussion. Longkong pericarp chilling injury (CI) index and ion leakage severely increased in the control fruits as compared with MeJA treated fruit. The increased of pericarp phenylalanine ammonia lyase (PAL), polyphenol oxidase (PPO) and peroxidase (POD) activities were well controlled by MeJA treatments. Fruit polygalacturonase (PG), pectin methyl esterase (PME) and lipoxygenase (LOX) activities were significantly controlled in MeJA treated fruit. Fruit superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX) activities found higher level in the MeJA treated fruit. Conclusion. The different concentrations of MeJA treatment effectively reduced the severity of physiological and biochemical quality changes in longkong fruit under prolonged low temperature storage

Physicochemical and Antimicrobial Characterization of Chitosan and Native Glutinous Rice Starch-Based Composite Edible Films: Influence of Different Essential Oils Incorporation

Biopolymer-based edible packaging is an effective way of preserving food while protecting the environment. This study developed an edible composite film using chitosan and native glutinous rice starch (NGRS) and incorporated essential oils (EOs) such as garlic, galangal, turmeric, and kaffir lime at fixed concentrations (0.312 mg/mL) to test its physicochemical and antimicrobial properties. The EO-added films were found to significantly improve the overall color characteristics (lightness, redness, and yellowness) as compared to the control film. The control films had higher opacity, while the EO-added films had slightly reduced levels of opacity and produced clearer films. The tensile strength and elongation at break values of the films varied among the samples. The control samples had the highest tensile strength, followed by the turmeric EO-added samples. However, the highest elongation at break value was found in the galangal and garlic EO-added films. The Young’s modulus results showed that garlic EO and kaffir lime EO had the lowest stiffness values. The total moisture content and water vapor permeability were very low in the garlic EO-added films. Despite the differences in EOs, the Fourier-transform infrared spectroscopy (FTIR) patterns of the tested films were similar among each other. Microstructural observation of the surface and cross-section of the tested edible film exhibited smooth and fissureless patterns, especially in the EO-added films, particularly in the galangal and kaffir lime EO-added films. The antimicrobial activity of the EO-added films was highly efficient against various gram-positive and gram-negative pathogens. Among the EO-added films, the garlic and galangal EO-added films exhibited superior inhibitory activity against Escherichia coli, Salmonella Typhimurium, Listeria monocytogenes, Staphylococcus aureus, and Pseudomonas fluorescence, and turmeric and kaffir lime EO-added films showed potential antimicrobial activity against Lactobacillus plantarum and L. monocytogenes. Overall, this study concludes that the addition of EOs significantly improved the physicochemical and antimicrobial properties of the CH-NGRS-based edible films, making them highly suitable for food applications

Effect of Palm Oil–Carnauba Wax Oleogel That Processed with Ultrasonication on the Physicochemical Properties of Salted Duck Egg White Fortified Instant Noodles

The present study permutes edible palm oil (PO) into oleogel by incorporating carnauba wax (CW) at two different concentrations (5 g/100 g and 10 g/100 g, w/w) and processing using ultrasonication. The prepared oleogels (OG1: PO-CW (5 g/100 g); OG2: PO-CW (10 g/100 g); and OGU1: PO-CW (5 g/100 g) with ultrasonication, and OGU2: PO-CW (10 g/100 g) with ultrasonication) were compared with PO (control) to deep fry salted duck egg white (SDEW) fortified instant noodles. The impact of different frying mediums on the physicochemical properties of SDEW noodles was investigated. SDEW instant noodles that were fried using OGU and OG samples had a higher L* and b* but lower a* values than those that were fried in PO (p p p p < 0.05). During storage of the frying medium after frying the noodles, OGU and OG had higher oxidative stability with lower TBARS, PV, p-AnV, and Totox values than PO at room temperature for 12 days. Overall, using oleogel as frying media improved the physicochemical and nutritional properties of SDEW noodles. This finding could be beneficial for food industries to produce healthy fried food products for consumers

Influence of prolonged ambient storage condition on the physicochemical properties of uncooked and cooked salted duck egg yolk

Salted duck egg yolk (SDEY) is rich in numerous beneficial nutrients, particularly proteins and fatty acids, and can be used in various edible condiments. However, uncooked SDEY can readily deteriorate when stored under ambient condition. Thus, the present study examined the changes in the shelf life of SDEY in uncooked and cooked forms stored under ambient condition (28 ± 5 °C) for 15 days. The SDEY was tested every 3 days for various physicochemical properties. The color attributes of SDEY, such as lightness (L*), redness (a*), and yellowness (b*), experienced a notable increase when cooked. This enhancement in color parameters was further amplified with ongoing storage. Additionally, the total color change (ΔE) exhibited a similar upward trend, with cooked SDEY displaying significantly higher values compared to the uncooked samples. The moisture content of SDEY was higher in uncooked samples than the cooked SDEY. On the other hand, water activity was not significantly different between the two samples. Additionally, the uncooked SDEY displayed a significantly higher pH level than the cooked SDEY. Notably, the pH values remained unaffected by the extended storage period. The total salt content was similar in both uncooked and cooked SDEY samples, yet both demonstrated a consistent decrease over extended storage periods. Similarly, all samples experienced a continuous decline in textural characteristics during the storage period. Notably, the cooked samples exhibited increased hardness, cohesiveness, springiness, and chewiness, in contrast to the uncooked SDEY, which showed a higher prevalence of adhesiveness. The total plate count and yeast and mold growth of SDEY continuously increased with storage, but cooked SDEY demonstrated better control against microbial growth. Overall, this study found that cooked SDEY is a better and more economical option for storage under ambient condition compared to the uncooked samples