Effect of vacuum mixing on the quality characteristics of fresh noodles

Study on the shelf life and quality characteristics of highland barley fresh noodles as affected by microwave treatment and food preservatives

In this work, the effect of microwave (MW), ε-poly-L-lysine (ε-PL), calcium propionate (CP), and their combinations on the shelf life and quality characteristics of highland barley fresh noodle (HBFN) was studied. Firstly, the mixed flour was treated by MW (800 W) for different time. Subsequently, HBFN was prepared by mixing flour and sterilized water with addition of 0.04% ε-PL combined with different concentrations of CP (0.025%, 0.020%, 0.015%) and stored at 25 ± 1°C. Changes of total plate count (TPC), moisture content, water state, textural properties, color, and pH in HBFN were monitored during storage. The results indicated that microwave treatment (40 s) provided 30% reduction of initial TPC of the flour without decline of noodle quality. Shelf life of HBFN treated with MW + ε-PL (0.04%) + CP (0.02%/0.025%) reached 80 and 88 hr, respectively, and had good edible qualities during storage.

Quality characteristics of fresh wet noodles treated with nonthermal plasma sterilization

Nonthermal plasma treatment has been a widely acknowledged effective method for food sterilization. This study presents the potential of nonthermal dielectric barrier discharge (DBD) plasma treatment for sterilization of the surface of the fresh wet noodles (FWNs). The plasma treatment achieved a more than one logarithmic reduction of the total bacterial count and total mold count as measured by counting the total microorganisms and filamentous fungi, respectively. In addition, the qualities of FWNs exposed to nonthermal DBD plasma treatment had no undesirable changes to color, texture, acidity and water distribution as measured by a texture analyzer, color meter and low-field nuclear magnetic resonance (LF-NMR), respectively. Thus, nonthermal DBD plasma treatment is a promising alternative to the traditional sterilization method applied in FWN industry and provides a new idea for the preservation and processing of fresh food.

Effects of Chitosan and Natamycin on Vacuum-Packaged Phyllo: A Pastry Product

The effects of vacuum packaging, chitosan (1.5%, w/v), and natamycin (10 mg/L, w/v) on phyllo pastry quality were studied by monitoring microbiological, chemical, and sensory changes. Five lots were prepared with or without vacuum packaging, chitosan, and natamycin: A, air packaged (control); V, vacuum packaged; VC, vacuum packaged with chitosan; VN, vacuum packaged with natamycin; and VCN, vacuum packaged with both chitosan and natamycin. Based on the sensory acceptability data, a shelf life of 6 (A), 12 (V), 14 (VN), 16 (VC), and 17 (VCN) days was obtained at 4°C. VCN treatment resulted in a shelf life extension of 11 days compared with the shelf life of the control. Microbiological data revealed that the combination of chitosan and natamycin resulted in significant reductions of microbial species (mesophilic total viable counts, yeasts and molds, psychrotrophic bacteria, lactic acid bacteria, Enterobacteriaceae, and enterococci) of 1 to 3 log CFU/g on the final day (day 18) of storage. Results suggest that the combination of chitosan and natamycin, which is an effective antifungal agent, can delay the spoilage of phyllo pastry while maintaining acceptable sensorial characteristics and the original freshness and appearance of the product.

Effects of dough mixing time before adding konjac glucomannan on the quality of noodles

In this study, effects of 5% konjac glucomannan (KGM) blended with low-protein flour at different dough mixing duration on the properties of dough and noodles were investigated. To prepare the KGM noodle samples, 5% KGM was added after low-protein flour mixed with water for 0, 2 and 4 min, respectively. The three samples above were defined as T₀ KGM, T₂ KGM and T₄ KGM noodle samples, respectively. The results revealed that the elastic modulus (G') and viscous modulus (G″) of dough both increased with extending dough mixing time before adding KGM. T₄ KGM samples showed the least cooking loss. Textural properties including hardness, cohesiveness and tensile strength of KGM noodles had a tendency to increase with a longer dough mixing time before adding KGM. Microstructure of dough and noodles confirmed that a longer dough mixing time before adding KGM made microstructure more compact with a thickened gluten matrix. The sensory quality of the T₂ KGM and T₄ KGM samples was better than that of the T₀ KGM samples.

Physicochemical Properties of A- and B-type Granules of Wheat Starch and Effects on the Quality of Wheat-Based Noodle

This work fractionated native wheat starches into A- and B-type granules fractions to accurately assess granules physicochemical properties and effects on water distribution, storage modulus (E′) and loss modulus (E″) of two type noodles with A- and B-type granules. Pasting viscosity and starch crystallization of A- and B-type granules were determined by Rapid Visco Analyzer (RVA) and X-ray diffraction (XRD) respectively. The noodles were prepared from wheat flour, which 20 % was replaced with the A or B starch fractions, respectively. The water distribution and dynamic mechanical properties of noodles were characterized through Low-field Nuclear Magnetic Resonance (LF-NMR) and Dynamic Mechanical Analysis (DMA). The results demonstrated that A- and B-type granules almost had a round shape with smooth surface. The crystal models of A- and B-type granules were the same but the relative crystallinity were different. A-type granules contained higher starch content, higher ratio between amylose and amylopectin and less damaged starch than B-type granules. B-type granules easily aggregated into clump in deionized water. A- and B-type granules were different in swelling properties and pasting viscosity under the same conditions. A-type granules possessed lower swelling power and water-binding capacity, higher solubility and pasting viscosity than B-type granules. A-noodles (relative to B-noodles) had higher ratio of immobilized water, E′ and E″.