Sweetness Evaluation of Mixtures of Fructose with Saccharin, Aspartame or Acesulfame K

Some sensorial properties of synthetic sweeteners are limiting factors for use in low calorie soft drinks, By combining synthetic sweeteners with small fructose additions, these limitations can be overcome. Using paired comparison evaluation tests, nonlinear sweetness/concentration relations were established against sucrose, in acidified noncarbonated mineral water, for fructose, saccharin, aspartame and Acesulfame K. In binary combinations with fructose, sweetness additivity was demonstrated, for each of the three synthetic sweeteners. This is in contrast with literature reporting specific synergistic effects. By taking advantage of the high relative sweetness of fructose, low calorie soft drinks containing as little as 2–3% sugar could not be distinguished sensorially from traditional sucrose drinks.     

Textural,Color, Hygroscopic,Lipid Oxidation,and Sensory Properties of Cookies Containing Free and Microencapsulated Chia Oil

Encapsulation of chia oil might protect omega-3 and omega-6 from lipid oxidation when producing baked foods. However, the actual gain in stability given by chia oil must be determined. In this work, chia oil or chia oil-loaded microparticles were added to a cookie formulation in order to evaluate the ability of the microcapsules in protecting chia oil from deterioration. Texture, color, water sorption isotherms, and sensorial properties were also evaluated. A hot homogenization technique was used with carnauba wax as an encapsulant, and the freeze-dried microparticles were incorporated into the cookie dough. Principal component analyses were carried out to evaluate lipid oxidation using the medium infrared spectra of the lipid fraction extracted from the baked cookies. It was found that the microencapsulated chia oil was better protected from oxidative deterioration during baking compared to the sample containing non-encapsulated chia oil. Textural analysis showed that chia oil (free and microencapsulated) acted as a coating on the wheat flour particles. Control cookies (no chia oil loaded) presented a more hydrophilic character. In the case of oil-loaded samples (free and microencapsulated), the isosteric heat of sorption behavior indicated an initial swelling step of the food polymers, resulting in the exposure of sorption sites of higher binding energies not previously available, and that this is because of the wheat particles being covered by the chia oil and the solid lipid microparticles. Furthermore, food acceptability did not change when the oil-loaded microparticles were added to the cookie formulation.     

Morphological,Thermal, Pasting,and Rheological Properties of Barley Starch and Their Blends

Native barley starch, as well as its blends with corn, wheat, and rice starch at different ratios of 75:25, 50:50, 25:75 were examined in terms of morphology, thermal, pasting, rheological, and retrogradation properties. Amylose content varied between 10.9–41.4% in rice, corn, wheat, and barley while it ranged from 18.02–38.40% in blends of barley starch with rice, corn, and wheat. A rapid visco analyzer showed that barley starch and its blends having low amylose content exhibited higher peak viscosity, breakdown, and setback than the high-amylose-containing starches and their blends. Amylose content was found to be negatively correlated with swelling power while it exhibited nonlinear relationship with solubility index. The transmittance of starch suspension stored at 4°C decreased during storage up to 6 days. Barley starch granules were largest (<110 μm) in size followed by wheat (<30 μm), corn (<25μm) and rice (<20μm) starches. Gelatinization temperatures (To, Tp, Tc) and enthalpies of gelatinization (ΔHgel) of starches from different sources also differed significantly. Corn and rice starches showed higher transition temperatures in general than those from wheat and barley; however, they showed higher ΔHgel values. Barley starch showed a higher tendency towards retrogradation than the cereal starches. Barley starch showed highest peak G′, G″ and lower tan Ð than corn, rice and wheat starches during the heating cycle. This study showed that the magnitude of changes in their properties during blending depends on the amylase content and morphological characteristics.     

Properties of Cookies Made with Natural Wax–Vegetable Oil Organogels

The aim of this study was to examine the feasibility of cookies in which the conventional margarine is replaced with an organogel of vegetable oil (VO) and natural wax. New cookies from VO organogels contain no trans fats and much less saturated fats than cookies made with a conventional margarine. To understand the effects of different kinds of waxes, organogels were prepared from 4 different waxes including sunflower wax (SW), rice bran wax (RBW), beeswax, and candelilla wax and properties of cookie dough and cookie were evaluated. To investigate the effects of different VOs on the properties of cookies, 3 VOs including olive oil, soybean oil and flaxseed oil representing oils rich in oleic acid (18:1), linoleic acid (18:2), and linolenic acid (18:3), respectively, were used. Both the wax and VO significantly affected properties of organogel such as firmness and melting behavior shown in differential scanning calorimetry. The highest firmness of organogel was observed with SW and flaxseed oil. Properties of dough such as hardness and melting behavior were also significantly affected by wax and VO while trends were somewhat different from those for organogels. SW and RBW provided greatest hardnesses to cookie dough. However, hardness, spread factor, and fracturability of cookie containing the wax–VO organogel were not significantly affected by different waxes and VOs. Several cookies made with wax–VO organogels showed similar properties to cookies made with a commercial margarine. Therefore, this study shows the high feasibility of utilization of the organogel technology in real foods such as cookies rich in unsaturated fats.     

Functional and Thermal Properties of Wheat, Barley, and Soy Flours and Their Blends Treated with a Microbial Transglutaminase

The effects of transglutaminase (TG) on the functional and thermal properties of wheat, barley, and soy flours and their blends were investigated. Free amino and thiol groups and aromatic hydrophobicity in samples were decreased with TG treatment (P < 0.05), confirming the polymerization of proteins in flours by TG treatment. TG‐treated samples had increased water‐holding capacity, fat adsorption, and emulsion stability, and slightly decreased emulsion activity. The addition of barley or soy to wheat flours decreased fat adsorption and emulsion stability, but these values increased, upon TG treatment of the same blended samples, to levels as high as for untreated wheat alone. TG treatment did not significantly affect the transition peak temperature of the flour samples. However, TG treatment lowered the transition enthalpy of wheat blended with barley or soy flour, and, conversely, increased that of wheat flour samples alone. Results suggest that protein cross‐linking by TG can produce unique and improved functionality even in wheat blended with barley or soy flour, and could provide opportunities for exploitation of this enzyme for product development.     

Physical Properties of WPI Films Plasticized with Glycerol, Xylitol, or Sorbitol

ABSTRACT: Effects of glycerol, xylitol, and sorbitol on selected physical properties of whey protein isolate (WPI) films were examined. Increasing glycerol or sorbitol content led to increases in moisture content, water vapor permeability, and % elongation; and decreases in tensile strength, elastic modulus, and glass transition temperatures of the films. Increasing levels of xylitol had no effect on permeability, moisture content, or glass transition temperature of the films, but decreased % elongation, tensile strength, and elastic modulus. Moisture content of the films correlated well with glass transition temperatures. Differences in measured physical properties of films with plasticizer type and concentration may be attributed to differences in the hygroscopic and crystalline properties of the plasticizers.     

Gluten‐Free Precooked Rice‐Yellow Pea Pasta: Effect of Extrusion‐Cooking Conditions on Phenolic Acids Composition,Selected Properties and Microstructure

Rice/yellow pea flour blend (2/1 ratio) was used to produce gluten‐free precooked pasta using a single‐screw modified extrusion‐cooker TS‐45. The effect of moisture content (28%, 30%, and 32%) and screw speed (60, 80, and 100 rpm) on some quality parameters was assessed. The phenolic acids profile and selected pasta properties were tested, like pasting properties, water absorption capacity, cooking loss, texture characteristics, microstructure, and sensory overall acceptability. Results indicated that dough moisture content influenced all tested quality parameters of precooked pasta except firmness. Screw speed showed an effect only on some quality parameters. The extrusion‐cooking process at 30% of dough moisture with 80 rpm is appropriate to obtain rice‐yellow pea precooked pasta with high content of phenolics and adequate quality. These pasta products exhibited firm texture, low stickiness, and regular and compact interne structure confirmed by high score in sensory overall acceptability.     

Comparison of Temporal Perception of Fruitiness in Model Systems Sweetened with Aspartame, an Aspartame + Acesulfame K Blend, or Sucrose

Sweetness and fruitiness of equisweet solutions of aspartame (APM), an aspartame + acesulfame-K blend (APM/AK) or sucrose were evaluated in binary (BIN) (sweetener and orange flavor) and tertiary (TER) (BIN and citric acid) systems by time-intensity (TI) methodology. Sweetener solutions adjusted to the viscosity of sucrose (APM* and APM/AK*) showed small inconsistent differences from their unthickened counterparts. In BIN systems, APM and APM* had the longest duration (DUR) of sweetness and fruitiness. In TER systems, APM* increased maximum intensity (MAX) and DUR of fruitness and S decreased sourness MAX and DUR relative to APM and APM/AK blends. Fruitiness MAX was perceived later than sweetness, whereas sweetness DUR persisted longer than fruitiness.     

Effect of Calcium on Acrylamide Level and Sensory Properties of Cookies

Thermal process contaminants including acrylamide and hydroxymethylfurfural have been an intensive area of research in recent years. The main pathway of acrylamide formation is linked to the Maillard reaction. The first step is the formation of Schiff base between the carbonyl and α-amino group of asparagine. Presence of cations partially or completely eliminates the formation of Schiff base. This study aimed to investigate the effects of calcium chloride and calcium lactate on acrylamide and hydroxymethylfurfural levels in cookies. The effects of calcium derivatives on the sensory properties of cookies were also investigated. A direct relationship was determined between the amount of calcium in recipe and acrylamide formed in cookies. Addition of 1.0% of Puracal Act 100 decreased acrylamide concentration of cookies from 128 ± 10 ng/g to 24 ± 4 ng/g. In the same time, hydroxymethylfurfural concentration increased from 2.0 ± 0.19 mg/kg to 3.3 ± 0.24 mg/kg by the addition of 1.0% of Puracal Act 100. The calcium derivatives had no effect on cookie diameter and thickness, but the surface colors were different. The use of calcium significantly increased the lightness (L*) parameter, but decreased the redness (a*; p < 0.05). The sensory properties of cookies in terms of sweetness, saltiness and bitterness were not significantly affected by the addition of calcium derivatives at dosages up to 0.5% (p > 0.05).     

肌球蛋白-琼脂混合凝胶的特性

比较肌球蛋白、琼脂、肌球蛋白-琼脂3 种凝胶样品的质构特性、流变特性和超微结构,并研究不同pH值（pH 5、6、7）和不同离子强度（0.2、0.4、0.6）条件下肌球蛋白-琼脂混合凝胶的特性变化。结果表明：肌球蛋白-琼脂混合凝胶的硬度和弹性明显大于纯肌球蛋白凝胶或纯琼脂凝胶（P＜0.05）,且均在pH 6时获得最大值;肌球蛋白-琼脂混合凝胶的硬度和弹性随离子强度的增加而增加,在离子强度为0.6时出现最大值;在肌球蛋白溶液中加入琼脂,无论在加热过程还是降温过程中,混合凝胶的储能模量（G’）和损耗模量（G’’）均显著高于相同温度条件下的纯肌球蛋白凝胶或纯琼脂凝胶（P＜0.05）;在冷却过程中,琼脂对G’和G’’的贡献超过肌球蛋白;用扫描电子显微镜观察肌球蛋白-琼脂混合凝胶（肌球蛋白、琼脂质量浓度分别为10、4 mg/mL）的超微结构时发现,混合凝胶为相分离型凝胶,琼脂为连续相,肌球蛋白为分散相。