Impact Of Long-Term Storage On The Instrumental Textural Properties Of Frozen Common Carp (Cyprinus Carpio,L.) Flesh

The aim of the work was to measure and confirm changes in the qualitative properties of frozen carp flesh (Cyprinus carpio L.) during 84 days of storage at -20°C, using instrumental texture profile analysis focused on hardness, cohesiveness, and springiness. Hardness in fresh fish was 2.908 N, in fish stored 28 days 1.238 N, after 56 days 0.505 N, and after 84 days 0.491 N. Cohesiveness (dimensionless unit) in fresh fish was 0.838, after 28 days 0.740, after 56 days 0.720, and after 84 days 0.712. Springiness (dimensionless unit) in fresh fish was 0.682, after 28 days 0.625, after 56 days 0.577, and at 84 days of storage 0.534. The texture profile analysis effect was determined by several regression and linear models. It is possible to calculate a certain time period in which changes develop up to the level of 50% of deterioration—in hardness 17.5 days and in cohesiveness 12.9 days, as this was proven to a defined significance level (P > 0.01). Only changes in springiness showed a linear regression in the level of 0.002 (rounded) for each day. Studies showed that the intensity of the most important changes in instrumental textural properties occurred during the initial 56 days after freezing and after up to 84 days of storage the changes continued at a lesser rate.     

Effect of Cultivars and Thermal Processing with Salt Solutions on the Textural Attributes (Hardness,Chewiness and Rate of Softening) of Potatoes (Solanum Tuberosum L.)

The change in textural attributes (hardness, chewiness and rate of softening) of three potato cultivars (Russet Burbank, Desiree and Sebago) was investigated. Uniform cylindrical samples (35-mm diameter and 3-mm thick) were prepared and exposed to different thermal processing regimes including; heating at 85°C, 95°C in water and steaming (100.2°C). The effect of salt on these textural attributes was also investigated using different salt concentrations (1.5%, 3% and 6% (w/w) NaCl). After thermal treatments the samples were subjected to texture profile analysis. The instrumental textural attributes were greatly affected by the cultivars and the thermal processing regimes. The change in textural attributes upon steaming was only marginally different compared to that at 95°C in water. Low concentrations of salt (1–3%) were found to accelerate the softening of the texture in these cultivars especially at lower temperatures. The textural attributes were modelled using a two-parameter reaction kinetics model. There was reasonable agreement by the model findings on the textural attributes prepared from all the thermal processing regimes and in presence and absence of (within average absolute error of 1.9–7%). Further, the model indicated that the order of reaction varied from 1.15–2.18 indicating that the changes in textural attributes in these thermal processing regimes followed higher reaction orders.     

Effect of Drying and Roasting on the Quality Attributes of Fufu Powder

Abstract

The effect of drying and roasting on the physicochemical and sensory qualities of fufu powder were investigated. The four samples of fufu: cooked dried fufu, cooked roasted fufu, dried fufu slurry and roasted fufu slurry, respectively, were subjected to physicochemical and sensory analysis. The water binding index, water solubility index, and water absorption index, varies between 3.44 and 0.17 (g/g sample), 0.07 and 0.01 (g/g), and 4.73 and 0.83 (g/g) respectively, while the starch damage and amylose content varies between 50.8% and 0.4%, 10% and 13% respectively, with roasted fufu slurries recording the highest values. The proximate composition of dried and roasted fufu samples showed the values of fat (0.6%–0.4%), protein content (0.2%–0.1%), ash content (37.8%–1.0%), moisture content (8.2%–10.2%), crude fibre (1.25%–8.5%) and carbohydrate content (43.0%–84.65%) respectively. Generally, there were no appreciable differences in the proximate composition of dried fufu samples. The pasting temperature of fufu samples varies from 78 to 95°C with roasted fufu slurries recording the highest values. The peak viscosity of dried fufu samples ranges between (80 and 900BU) and viscosity at 50°C ranges between (260 and 460BU). There are no significant differences (P > 0.01) for the sensory qualities in term of color, taste, and overall acceptability except for odor and texture at (P < 0.01).     

Influence of Drying Temperature and Rehydration on Selected Textural Properties of Carrots

Cubes of carrots dried at 60, 70, 80, and 90°C were rehydrated up to 180 min at 20°C and up to 10 min at 95°C. Kinetics of cutting strength were determined for the samples soaked at 95°C. Compression stress relaxation behavior of the samples was studied on carrots rehydrated at 20 and 95°C. Kinetics of cutting strength were satisfactorily described by means of a first-order kinetic model. The compression stress relaxation of carrots was analyzed using five element Maxwell and empirical Peleg models. Both of the models were found to be appropriate for characterizing viscoelastic properties of dried and rehydrated carrot cubes. The results indicated that the use of low drying temperatures was suitable for preserving the quality attributes of carrots after rehydration, and drying air temperature of 60°C was chosen as the most appropriate for hot air processing of carrots.     

Textural and colour changes during storage and sensory shelf life of muffins containing resistant starch

The effect on baked muffins of progressively replacing wheat flour with resistant starch (RS) (26/0, 21/5, 16/10, 11/15 and 6/20) was studied. In this study, texture profile analysis (TPA) and the elastic recovery test were used to evaluate the effects of RS on the textural properties of fresh and stored muffins (from 0 to 16 days). Textural parameter values decreased with the increase of RS; springiness and cohesiveness reflected better than the textural differences for fresh muffins. Changes in the textural parameter values with storage time were smaller at higher RS levels. Survival analysis methodology was used to estimate the changes in muffin shelf life. Shelf life time of control muffin is higher than 20% RS muffin for 25% consumer rejection but this behaviour is the opposite for 50% consumer rejection.     

Variations of Hausdorff Dimension and Selected Textural Indices of Cheddar and Gouda Cheeses During Storage

Two imported commercial cheeses (Cheddar and Gouda) were analyzed to characterize their textural changes during a storage period from 176 to 362 days at 4°C. Fractal dimension analysis was used to examine the structure of the cheeses, and a scaling model based on stress values was used to calculate fractal dimension (D_f) by the Hausdorff dimension count method. It was found that the variation of D_f of two cheeses showed a similar trend. When two cheeses were stored from 176 to 300 days, their D_f ranged from 2.37 to 2.43 for Cheddar or from 2.06 to 2.23 for Gouda cheeses. After that, the final values of D_f increased obviously to 2.87 (Cheddar cheese) or 2.63 (Gouda cheese) at the end of the storage period. The experiments carried out showed that the variation of D_f had a poor relationship with the changes of pH 4.6 soluble nitrogen and two instrumental textural indices (hardness and springiness) of the cheeses, especially in the late storage period, but the inhomogeneous cavities existing in the cheeses could be reflected by their D_f.     

Quality Attributes of Fruit Bar Made from Papaya and Tomato by Incorporating Hydrocolloids

Fruit bar was prepared from blend of ripe papaya and tomato pulps (variety, Red Lady and C.V. Naveen, respectively) in the ratio 75:25 on weight basis. Effects of hydrocolloids viz. pectin (P), starch (S), and ethyl cellulose (EC) and its three different levels on physico-chemical, sensory, and textural characteristics were investigated. It was found that seven different samples of fruit bar had moisture contents of 20.9–22.1% and total soluble solids 78.1–78.8°Brix while pH, browning index, and vitamin C contents were in the following ranges, 4.3–4.50, 0.137–0.150 (OD), and 40.5–41.4 mg/100 g respectively. Texture study revealed that hydrocolloids incorporation at 1% each of starch + ethyl cellulose and pectin + starch, 1.5% each caused significant (P < 0.05) increased in compactness/hardness of texture. Sensory characteristics study revealed that all the samples of fruit bar were acceptable in taste, color, and aroma but differed significantly (P < 0.05) in their texture. The samples packed in LDPE bags (100 μ), stored at 35–45°C for four months. It was found that there were significant (P < 0.05) changes in physico-chemical properties like acidity and vitamin C during four months storage. No significant (P < 0.05) effect on either browning index (OD) or deterioration in color, taste, and aroma of these samples was observed. During four months storage change in color and texture were not uniform for all treatments. Addition of 0.5 and 1% of each starch + ethyl cellulose were effective in maintaining the color while 0.5, 1, and 1.5% of each P + S was effective in improving the texture during four months storage.     

Freezing and Freezing-Thawing Cycles on Textural and Biochemical Changes of Meagre (Argyrosomus regius,L) Fillets During Further Cold Storage

The effects of freezing and freezing-thawing cycles during cold storage have been studied in meagre (Argyrosomus regius) fillets. Fillets were subjected to three conservation protocols: fresh, freezing at –20°C, and repeated freezing-thawing cycles. Fresh fillets were stored (4°C, 15 days), and the same protocol was followed for freezing and freezing-thawing after the freezing period. Freezing and freezing-thawing fillets were softer and presented lower water holding capacity than fresh, mostly attributable to collagen solubilization, and partial myofibrillar protein degradation. Cold storage (4°C) during 15 days caused softening in fresh and frozen fillets attributable to myofibrillar protein hydrolysis. Freezing-thawing cycles increased proteolysis, this leading to unacceptable softening even from early stages of further cold storage, and this was also revealed by SDS-PAGE.     

Textural and microstructural properties of Kradi cheese (an indigenous cheese of Jammu and Kashmir,India)

The texture and microstructure of Kradi cheese, an indigenous fresh unripened cheese of Jammu and Kashmir, India, were studied. There were significant differences (P < 0.05) for hardness, adhesiveness, springiness, cohesiveness, chewiness and resilience between samples from four different market areas. The optimised products made in the laboratory from cultures NCDC‐167 and NCDC‐144 showed significant differences (P < 0.05) in the textural and mechanical properties of tensile strength. The microstructure of the market samples was distinguished by the greater size of the voids present in three‐dimensional casein network. The optimised laboratory product had a more compact and fibrous structure compared to the market samples, which was attributed to its higher protein content.     

Effect of sun-drying on microstructure and texture of S. Bartolomeu pears (<Emphasis Type="Italic">Pyrus communis</Emphasis> L.)

Histological and mechanical studies were conducted to evaluate the changes that are conferred by a traditional sun-drying process on the texture and microstructure of a Portuguese pear cultivar (Pyrus communis L. var. S. Bartolomeu). Sun-drying processing of the pears results in loss of water, cell flattening and shrinkage, loss of cellular adhesion, and even loss of cell wall integrity. The sun-drying process significantly reduced the hardness and fracturability of the pear tissues, while increasing their cohesiveness, springiness and adhesiveness. The results obtained by texture and microstructure analysis of the fresh pear flesh reflect essentially an unified matrix comprising well-packed cells strongly bonded together whereas those of the sun-dried pear flesh pointed out a soft solid with many individual cells distributed in a soft matrix, explaining its softer and chewy texture.     

Textural and viscoelastic properties of pork frankfurters containing canola-olive oils, rice bran, and walnut

Textural, rheological and microstructural properties of frankfurters made with 20% pork backfat, 20% canola or 20% canola-olive (3:1) oils, including rice bran (RB) and walnut extract (WE) as macronutrients (2.5%) were investigated. Textural parameters, including hardness, gumminess and rupture-force, were highly (P<0.05) influenced by the fat-oil composition. Addition of RB or WE in vegetable oil emulsions improved textural consistency (P<0.05). However, RB addition reduced gelling capacity, suggesting antagonistic interactions between fiber and oil droplets. Vegetable oil addition favored gel network formation, and, when combined with WE, showed the highest improvement of gel elasticity. These textural and gelling properties were corroborated by frankfurter micrographs, which revealed interactions between vegetable oils, RB, or WE with protein matrix and fat globules affecting these parameters. The results suggest that functional plant-derived ingredients can be valuable to the modification of frankfurter formulations for improved nutrition and as well as textural quality.     

茶叶贮藏过程中含水量变化及其影响因素研究

本研究通过对不同初始含水量、不同温度和不同包装的茶叶在贮藏过程中含水量的测定，发现贮藏茶叶含水量变化呈曲线上升趋势，并且增速先快后慢；初始含水量低的茶叶贮藏中的吸湿速度和吸湿量均大于初始含水量高者；但在低温和采用防潮性能好的包装条件下贮藏茶叶，初始含水量高低的影响就不很明显。     

Physicochemical,Textural, Pasting,and In Vitro Digestion Properties of Some Basmati and Non-Basmati Rice Cultivars

Grain quality attribute tests based on physicochemical, textural, pasting, and in vitro digestion properties of eight different rice cultivars were studied. Basmati varieties showed higher values of amylose content, iodine absorption, blue value, hardness, cohesiveness, pasting temperature, and set back, whereas swelling power, solubility, adhesiveness, peak viscosity, and breakdown values were found to be higher in non-basmati varieties. The release of maltose from basmati rice flour (23.12–25.86 mg/g rice flour) was found to be slower as compared to non-basmati ones (27.43–28.36 mg/g rice flour). Amylose content showed significant correlations with different quality parameters at 5% level of significance.     

梨体外模拟胃肠消化过程中多酚、黄酮及抗氧化活性的变化规律

通过体外模拟胃肠消化法模拟梨(鸭梨、蜜梨和香梨)在胃肠道的消化过程,测定模拟胃肠消化过程中抗氧化活性物质(以多酚表示)和黄酮的释放量及总抗氧化活性的变化规律。结果显示,模拟胃环境消化过程中,与消化0 h相比,鸭梨、蜜梨和香梨的多酚最大释放量是其2.11、1.51、2.24倍,黄酮最大释放量是其1.51、1.92、2.67倍,最大抗氧化活性是其1.79、1.79、3.12倍;模拟肠环境消化过程中,与胃消化0 h和肠消化0 h相比,鸭梨、蜜梨和香梨的多酚最大释放量分别为其1.83、1.99、2.58倍和0.92、1.17、1.18倍,黄酮的最大释放量分别为其0.90、1.21、1.79倍和0.49、0.63、0.63倍,最大抗氧化活性分别为其2.78、2.15、3.42倍和1.34、1.42、1.12倍。这表明,梨在模拟胃肠消化过程中,胃蛋白酶、胰酶及胃酸均可以促进抗氧化活性物质释放,释放的抗氧化活性物质可能来自多酚与蛋白质、多糖、脂质等形成的复合物的水解。     

Instrumental Textural and Rheological Properties of Raw,Dried, and Cooked Noodles with Transglutaminase

Textural and rheological properties of raw, dried, and cooked noodles with microbial transglutaminase were evaluated by an instrumental texture analyser. Generally, the strength of the noodles significantly increased with microbial transglutaminase concentration from 0 to 1.0%. The cutting force of raw noodle is a good indicator to predict the strength of dried and cooked noodle products. Mechanical stress relaxation data of cooked noodles were fitted well by both Maxwell and Peleg-Normand models. The fitted parameters, λ₁ and k₂, were more sensitive to the changes in viscoelastic properties than k₁ and %SR. Significant correlations were found between textural characteristics and stress relaxation parameters. Results of this study suggest that dried or cooked noodle with good quality can be produced by incubating with 0.5–1.0% microbial transglutaminase for 30 min at 30?°C.     

Drying of yellow pea starch on inert carriers: Drying kinetics,moisture diffusivity,and product quality

This study aimed at investigating the drying of yellow pea starch dispersions on inert solid carriers and determining the drying kinetics, moisture diffusivity and the product quality, quantified through damage index and final moisture content. Drying kinetics accomplished in a convective drying tunnel show that the overall mass transfer is controlled by internal migration of moisture within the starch particles. For a given inlet air temperature from 100 to 180 °C, the apparent diffusion coefficient derived from the drying curves increases exponentially with the instantaneous moisture content, with values ranging from 4 × 10⁻¹¹ to 3 × 10⁻⁸ m²/s. Due to low diffusivity and the thin coat formed on the surface of solid carriers, the resistance to internal diffusion is negligible as compared to the overall mass transfer resistance when drying of starch dispersions takes place on inert solid carriers. Drying of yellow pea starch dispersion on Teflon particles as inert carriers was studied in laboratory and pilot fast spouted bed dryer for inlet air temperatures from 140 to 240 °C, and initial solid content of 38%, mass (d.b.). The starch damage index for targeted product moisture content was below 2.5% in the inlet air temperature range from 120 to 210 °C, when atomizing from the bottom of dryer.     

大豆贮藏蛋白11S和7S组分及其亚基相对含量的研究

选取晋大62与高蛋白品种诱处4号杂交亲本及后代的40个品系种子样品为材料,利用聚丙烯酰胺凝胶电泳技术(SDS-PAGE),得到贮藏蛋白的各个条带组分图,通过分析大豆贮藏蛋白11S和7S组分及其亚基的相对含量,来探索大豆贮藏蛋白11S和7S组分的关系及在育种上的利用。SDS-PAGE电泳图谱显示:亲本及杂交后代群体贮藏蛋白亚基的组成基本相同,没有出现亚基缺失现象,但是不同品系间各亚基存在显著变异。研究结果为今后提高大豆蛋白品质,选育优质大豆新品种提供了理论基础和实践依据。     

Effect of Vacuum,Microwave, and Convective Drying on Selected Parsley Quality

This article has been retracted.