Rheological,Physical, and Sensory Attributes of Gluten‐Free Rice Cakes Containing Resistant Starch

In this study the effect of resistant starch (RS) addition on gluten‐free cakes from rice flour and tapioca starch physical and sensorial properties was investigated. Increase in RS concentration made cake batters less elastic (drop of G'(ω), G''(ω) values) and thinner (viscosity decreased). Cakes specific volume increased with an increase in RS level and was maximized for 15 g/100 g RS, although porosity values were significantly unaffected by RS content. Crumb grain analysis exhibited a decrease in surface porosity, number of pores and an increase in average pore diameter as RS concentration increased. During storage, cake crumb remained softer in formulations with increasing amounts of RS. Sensory evaluation of cakes demonstrated the acceptance of all formulations, with cake containing 20 g/100 g RS mostly preferred. Gluten‐free cakes with improved quality characteristics and high nutritional value can be manufactured by the incorporation of RS.     

Rheological, Textural, Microstructural, and Sensory Properties of Sorbitol-Substituted Mango Jam

Production of low-calorie mango jam was investigated by substituting sucrose with sorbitol. Quality of sorbitol jam was evaluated with respect to rheological, textural, microstructural, color, and sensory attributes. Principal component analysis revealed that sucrose- and sorbitol concentration, hardness, and work of shear were the most relevant parameters in sorbitol jam manufacturing. Sorbitol-substituted mango jam behaved as pseudoplastic fluid exhibiting yield stress. The Herschel–Bulkley (HB) model described adequately the steady-state rheological behavior of jam. Temperature dependence of the consistency index followed Arrhenius relationship. Yield stress of the jam increased with total soluble solids (TSS) content during gelation process and decreased with increasing temperature. Time-dependent structural breakdown characteristics of mango jam followed Hahn model. Hardness of mango jam decreased with increasing sorbitol concentration because of weaker junction zones of pectin molecules. Lightness (L*) and yellowness (b*) decreased, but redness (a*) increased with TSS in mango jam for selected sorbitol levels. The mango jam manufactured at sorbitol level?=?70 with 75% sorbitol substitution received the highest overall acceptability score. Microstructure of sorbitol jam was found to be composed of network regions with large pores as well as dense, compact regions with small pores.     

结冷胶和谷氨酰胺转氨酶对牛肉凝胶持水性与硬度的影响

利用响应面法研究结冷胶(0.2％～1.0％)、谷氨酰胺转氨酶(0.2％～0.6％)、处理温度(40～60℃)和反应时间(120～160min)对牛肉凝胶持水性和硬度的影响及其相互作用.结果表明:谷氨酰胺转氨酶、处理温度和反应时间对牛肉糜凝胶蒸煮损失率和保水性的影响显著,谷氨酰胺转氨酶、处理温度和结冷胶对牛肉糜凝胶硬度的...     

Rheological Properties of Mixed Gels using Waxy and Non‐waxy Wheat Starch

Mixed starches with an amylose content of 5, 10, 18, 20, 23, and 25% were prepared by blending starches isolated from waxy and non‐waxy wheat at different ratios. The dynamic viscoelasticity of mixed 30% and 40% starch gels was measured using a rheometer with parallel plate geometry. The change in storage shear modulus (G′) over time at 5 °C was measured, and the rate constant of G′ development was estimated. As the proportion of waxy starch in the mixture increased, starch gels showed lower G′ and higher frequency dependence during 48 h storage at 5 °C. Since the amylopectin of waxy starch granules was solubilized more easily in hot water than that of non‐waxy starch granules, mixed starch containing more waxy starch was more highly solubilized and formed weaker gels. G′ of 30% and 40% starch gels increased steadily during 48 h. 30% starch gel of waxy, non‐waxy and mixed starches showed a slow increase in G′. For 40% starch gels, mixed starch containing more waxy starch showed rapidly developed G′ and had a higher rate constant of starch retrogradation. Waxy starch greatly influenced the rheological properties of mixed starch gels and its proportion in the mixture played a major role in starch gel properties.     

Effect of Surfactant Gels on Dough Rheological Characteristics and Quality of Bread

Sodium stearoyl-2-lactylate (SSL), diacetyl tartaric acid esters of monoglyceride (DATEM), glycerol monostearate (GMS), and distilled glycerol monostearate (DGMS) surfactant gels were made with water and varying shortening contents. The effect of these gels on dough rheological characteristics and quality of bread was investigated. Overall, the surfactant gels improved the farinograph and extensograph characteristics of wheat flour, but the improvement reduced to some extent with the presence of shortening in the gels. Alveograph data indicated that dough properties improved with the addition of surfactant gels. Shortening in gels showed varying influence on the dough alveograph properties of wheat flour. The results indicated that the surfactant gels changed the rapid visco analyzer characteristics of wheat flour, and the presence of shortening in gels further altered the characteristics. All surfactant gels improved the volume, specific volume, texture, and overall quality scores of bread, but the improvement varied for different surfactants. By increasing the addition of shortening in gels, though the quality characteristics further improved, the response to surfactants reduced by increasing shortening content.     

游离与微胶囊化益生菌对酸奶感官性质的影响

对游离益生菌与微胶囊化益生菌（嗜酸乳杆菌和双歧杆菌）的存活率、pH、胞外多糖的产生进行了比较,且对添加这两种形式的益生菌酸奶,在贮存7周后的感官性质进行了评定。结果表明,微胶囊有助于提高益生菌在酸奶中存活率,且添加游离或包埋益生菌的酸奶在贮存期间,其外观、色泽、风味及酸度并无显著变化,但酸奶的质地（光滑程度）变化显著。     

Starch and Amylopectin — Rheological Behavior of Gels

Rheological behavior of starch and amylopectin gels was evaluated by small amplitude oscillatory testing using the storage modulus (G′), loss modulus (G″) and the complex viscosity (n*). It was found for the three starches (normal and waxy corns, and amaranth) that at low frequency the viscous component G″ had a major contribution on the gel structure than the elastic G′ and that the complex viscosity (n*) diminished when the frequency was increased. Amaranth amylopectin showed G″ values higher than those of G′. Corn commercial and waxy corn amylopectins presented a similar behavior in the G′ values. Normal corn amylopectin gave the highest complex viscosity values.     

Selected Quality Factors and Sensory Attributes of Cured Ham as Influenced by Different Phosphate Blends

In each of four replications, 32 packer-style hams were randomly allotted to one of eight treatment groups in which the curing brine formulated for a 10% pump contained: (1) No phosphate; (2) 100% sodium tripolyphosphate (STP); (3) 5% sodium hexametaphosphate (SHMP) + 95% STP; (4) 10% SHMP + 90% STP; (5) 5% Quadrafos (SQ) + 95% STP; (6) 10% SQ + 90% STP; (7) 10% tetrasodium pyrophosphate (TSPP) + 90% STP; or (8) 20% TSPP + 80% STP. Raw hams were subjectively evaluated for quality, samples were removed for analysis, and hams were processed according to commercial procedures. Processing losses and cooking losses were calculated, and physical and sensory properties of the processed, cooked hams were measured. The 20% TSPP blend was least effective in reducing processing shrinkage; whereas, the 5% SHMP blend was the most effective. Nonphosphate treated hams had greater cooking losses and were scored lowest for all sensory attributes. Greater drip cooking losses occurred as amounts of SHMP and SQ increased in the phosphate blends.     

Effect of Hops Beta Acids on the Survival of Unstressed‐ or Acid‐Stress‐Adapted‐Listeria Monocytogenes and on the Quality and Sensory Attributes of Commercially Cured Ham Slices

This study evaluated the antilisterial activity of hops beta acids (HBA) and their impact on the quality and sensory attributes of ham. Commercially cured ham slices were inoculated with unstressed‐ and acid‐stress‐adapted (ASA)‐L. monocytogenes (2.2 to 2.5 log CFU/cm²), followed by no dipping (control), dipping in deionized (DI) water, or dipping in a 0.11% HBA solution. This was followed by vacuum or aerobic packaging and storage (7.2 °C, 35 or 20 d). Samples were taken periodically during storage to check for pH changes and analyze the microbial populations. Color measurements were obtained by dipping noninoculated ham slices in a 0.11% HBA solution, followed by vacuum packaging and storage (4.0 °C, 42 d). Sensory evaluations were performed on ham slices treated with 0.05% to 0.23% HBA solutions, followed by vacuum packaging and storage (4.0 °C, 30 d). HBA caused immediate reductions of 1.2 to 1.5 log CFU/cm² (P < 0.05) in unstressed‐ and ASA‐L. monocytogenes populations on ham slices. During storage, the unstressed‐L. monocytogenes populations on HBA‐treated samples were 0.5 to 2.0 log CFU/cm² lower (P < 0.05) than control samples and those dipped in DI water. The lag‐phase of the unstressed‐L. monocytogenes population was extended from 3.396 to 7.125 d (control) to 7.194 to 10.920 d in the HBA‐treated samples. However, the ASA‐L. monocytogenes population showed resistance to HBA because they had a higher growth rate than control samples and had similar growth variables to DI water‐treated samples during storage. Dipping in HBA solution did not adversely affect the color or sensory attributes of the ham slices stored in vacuum packages. These results are useful for helping ready‐to‐eat meat processors develop operational procedures for applying HBA on ham slices.     

Oil Coating Affects Internal Quality and Sensory Acceptance of Selected Attributes of Raw Eggs during Storage

Four (coconut, palm, rice bran, and soybean) edible oils and glycerol were applied on eggshell. All noncoated and coated eggs were stored for 5 wk at 25 ± 2 °C and drawn weekly for quality evaluation. All oil coatings were more effective in preserving internal quality of eggs than was glycerol coating. As storage time increased, the preservative effects of edible oil coating on weight loss, and albumen and yolk quality were significantly noticed. Oil‐coated eggs had significantly lower weight loss (<0.43%) than did noncoated (3.87%) and glycerol‐coated (3.73%) eggs after 5 wk of storage. Based on the Haugh unit, oil‐coated eggs maintained AA grade up to 3 wk. After 5 wk of storage, noncoated, glycerol‐coated, and oil‐coated eggs changed from AA grade to below B, below B and A grade, respectively. The albumen pH of noncoated and glycerol‐coated eggs considerably increased from 8.23 to 9.51 and 9.42, respectively, while those of oil‐coated eggs either maintained or slightly increased to 8.32. The albumen viscosity of all eggs decreased with increased storage time. Consumers (N = 120) could differentiate surface glossiness of oil‐coated eggs from uncoated eggs (R‐index of 81.42% to 86.99%). All oil‐coated eggs were acceptable for surface glossiness (liking scores of 6.22 to 6.77) and surface odor (liking scores of 6.20 to 6.55) with overall liking scores of 6.34 to 7.03. Overall, this study demonstrated that edible oil (coconut, palm, rice bran, and soybean) coating could preserve internal quality of eggs (maintaining grade A) at least 4 wk longer than noncoated eggs. Practical Application: Freshness is a major contribution to the egg quality. The internal quality of eggs begins to deteriorate after they have been laid due to loss of moisture and carbon dioxide via the eggshell pores. Refrigeration is very effective in preserving egg quality. Surface coating is an alternative method to preserve egg quality, although it is much less effective than refrigeration. This study demonstrated that coconut, rice bran, soybean, and palm oils, which are abundant and commonly consumed in many parts of the world, could preserve the internal quality and reduce weight loss of oil‐coated eggs during room temperature storage.