Yellow alkaline noodles (YAN) prepared by partial substitution of wheat flour with soy protein isolate and treated with microbial transglutaminase (MTG) and ribose were investigated during cooking. Cooking caused an increase in lightness but a decrease in redness and yellowness, pH, tensile strength and elasticity values of noodles. The extents of these changes were influenced by formulation and cross-linking treatments. The pH and lightness for YAN-ribose were lowest but the yellowness and redness were the highest whilst the tensile strength and elasticity values remained moderate. For YAN-MTG, the color and pH values were moderate, but tensile strength and elasticity values were the highest. YAN prepared with both cross-linking agents had physical values between YAN-ribose and YAN-MTG. Although certain sensory parameters showed differences in score, the overall acceptability of all 10-min-cooked YAN was similar. It is possible to employ cross-linking agents to improve physical properties of cooked YAN.

No abstract

Soy protein isolate‐yellow alkaline noodles (SPI‐YAN) prepared by partial substitution of wheat flour with SPI were treated with cross‐linking agents namely microbial transglutaminase (SPI‐MTG), ribose (SPI‐R) and the combination of both (SPI‐R‐MTG). SPI‐YAN were either unprocessed (UP), thermally processed at 121C for 30 min (P), or thermally processed and followed by 3 weeks storage at ambience (PS). The thermal, storage treatments and formulation had an impact on the physicochemical properties of SPI‐YAN. pH and textural parameters of P‐noodles were lower than those of UP‐noodles, while PS‐noodles showed higher water absorption, thickness, but lower textural parameters. For P and PS‐noodles, SPI‐R showed the highest retort cooking loss, water absorption, redness and yellowness, but the lowest in pH values, while SPI‐MTG exhibited the lowest retort cooking loss, thickness, yellowness, but the highest textural parameters. Scanning electron microscopy images indicated an enhanced network microstructure of SPI‐MTG and SPI‐R‐MTG following thermal processing and/or storage. Practical Application Thermal processing of canned noodles causes damage to overall structure and affects sensory appeals. The present work describes the effects of cross‐linking agents (microbial transglutaminase [MTG] and ribose) on the physicochemical and physical properties of canned soy protein isolate‐yellow alkaline noodles prepared by retort processing, and their impacts during storage. The main finding is that the use of MTG maybe helpful in improving retorted noodles' texture during thermal processing. This information can further stimulate the application of MTG in preserving the texture and edibility of canned noodles.

Pre‐gelatinised high‐amylose maize starch combined with Ca2+ ‐induced setting of alginate and their effect on rice flour noodle properties.

This study investigated the influence of pregelatinized high-amylose maize starch and chilling treatment on the physical and textural properties of canned rice noodles thermally processed in a retort. Rice noodles were prepared from rice flour partially substituted with pregelatinized high-amylose maize starch (Hylon VII™) in the ratios 0, 5, 10, and 15% (wt/wt). High-amylose maize starch improved the texture and brightness of fresh (not retorted) noodles. Chilling treatment led to significant (P ≤ 0.05) improvement in the texture of fresh noodles at all levels of substitution with high-amylose starch. The highest hardness was recorded at 15% amylose level in chilled nonretorted noodles. Retort processing induced a major loss of quality through water absorption, retort cooking loss, decreased noodle hardness, and lightness. However, the results showed that amylose and chilling treatment positively reduced the impact of retorting. For each level of amylose substitution, a low retort cooking loss and increased noodle hardness were associated with a chilling treatment. For both chilled and nonchilled noodles, retort cooking loss and hardness increased with increasing levels of amylose substitution.