Effect of oven temperature profile and different baking conditions on final cake quality

This study discusses the effect of airflow on oven temperature profiles, the internal cake temperature and the final cake quality. It was found that the presence of airflow reduced the oscillation in the oven temperature profile from 12.98–30.27% to 3.17–4.02%. The bottom of the oven chamber experienced the greatest reduction in temperature oscillation in the presence of airflow. During the second stage of baking with airflow, the heating rate was increased from 5.07 to 7.52 °C min^?1 and 8.35 °C min^?1 to the increase of the baking temperature from 160 to 170 °C and 180 °C, respectively. The cake volume expansion rate was also increased 5–10% during second stage when baking with airflow condition. The cakes baked in the presence of airflow had a more porous crumb texture and lower moisture content compared to the cakes baked without airflow.     

Instron measurement of sponge cake firmness: Effect of additives and storage conditions

Instron measurement and sensory analysis of sponge cake texture was performed under various conditions. The samples were compared on the basis of their storage in modified atmosphere (CO₂/N₂, 50:50 v) or not, at + 4°C or + 20°C, as whole cakes or slices of cake, and with or without additives (soya bean protein or sodium alginate). It was found that the best conditions for preservation of a soft texture in a whole cake are obtained in a modified atmosphere at +4°C when 10 g kg^?1 soya bean protein is included in the sponge cake formulation.     

剪切时间对脂肪微粒大小和肉糜品质的影响

为研究剪切时间对肉糜中脂肪微粒大小和品质的影响,研究分别测定4种不同剪切时间(1、3、5min和7min)下肉糜中脂肪微粒粒径大小和粒度分布特点、乳化稳定性和凝胶强度大小。结果表明,剪切时间为5min和7min的肉糜中脂肪微粒比较小、粒度均匀,乳化稳定性好,凝胶强度大,但这两处理组间差异并不显著(P>0.05)。因而,试验研究认为3000r/min剪切速度下剪切5min就可制成品质好的肉糜。     

添加谷氨酰胺转氨酶对糙米蛋糕品质的影响

研究在糙米蛋糕的蛋黄糊和蛋清中分别添加不同量的谷氨酰胺转氨酶(transglutaminase,TGase)对蛋糕烘焙品质的影响,并分析比较了TGase添加前后蛋黄糊和蛋清理化特性的变化。结果表明:添加TGase能显著提高糙米蛋糕的比容和弹性,降低其硬度,在蛋黄糊和蛋清中分别添加10和2 U/g TGase时,糙米蛋糕比容达到最大值6.0 mL/g。添加TGase后,蛋黄糊的黏度和乳化稳定性分别提高62.27%和3.86%,蛋清打发后的泡沫稳定性提高8.43%。通过测定发现蛋黄糊中的游离巯基含量明显减少,傅里叶变换红外光谱(fourier transform infrared spectroscopy,FTIR)和体积排阻高效液相色谱(size exclusion high performance liquid chromatography,SE-HPLC)的分析表明,添加了TGase的蛋黄糊中蛋白质β-折叠的比例显著增加,无规卷曲、β-转角的比例下降,并形成了更多大分子质量的蛋白质聚集体。这表明添加TGase促进了蛋黄糊和蛋清中的蛋白形成更多的交联,使蛋白质网络更加紧密,从而改善糙米蛋糕的质构。     

Original article: Influence of flour mill streams on cake quality

Wheat‐milling process generates different flour streams that differ in particle size, composition and functional and cake‐making properties. Particle size, composition and pasting properties of flour fractions (two from break and three from reduction system) obtained during milling of three wheats varying in protein content were determined. Shape, textural, colour and sensory analyses were performed on cakes prepared with the different mill streams. The final break and reduction streams had the highest protein and ash contents, pasting temperatures and the lowest starch percentage. Cakes prepared with the last streams showed higher batter density and lower volume. These results could indicate good air incorporation but deficient air distribution. Last streams cakes showed a darker, more reddish and yellowish crumb that was significantly related to flour colour characteristics. Because of these differences, such cakes obtained the lowest sensory scores. In this study, it has been verified that, to adapt flours to cake preparation, the final streams should be eliminated. The particle size of each stream is the most determinant parameter to obtain cakes with better volume and texture, being the flours with small particle size the most adequate.     

变性淀粉对海绵蛋糕品质影响

研究预糊化乙酰化二淀粉磷酸酯、预糊化玉米淀粉和预糊化羟丙基二淀粉磷酸酯对蛋糕比容、水分活度和组织结构等方面影响。结果表明:添加0.20%预糊化乙酰化二淀粉磷酸酯可增大蛋糕体积;添加0.40%~0.80%预糊化玉米淀粉对降低蛋糕水分活度效果明显;添加0.20%预糊化羟丙基二淀粉磷酸酯对延缓蛋糕老化效果最为显著。     

Influence of fat content and emulsifier type on the rheological properties of cake batter

The effects of fat content and emulsifier type on the rheological properties of cake batter have been investigated by using a parallel-plate rheometer. The apparent viscosity of cake batter with five different fat concentrations (0, 12.5, 25, 37.5, and 50%) and two types of emulsifier, namely Purawave and Lecigran, was studied as a function of the shear rate. In addition, the time dependency of different cake formulations was investigated. It was found that cake batter with different fat concentrations and emulsifier types exhibited shear thinning and time-independent behavior. Experimental data provided a good fit for the power law model. The increase in fat content and addition of emulsifier caused a decrease in the apparent viscosity. The flow behavior index was not found to be dependent on the composition of cake batter.     

Effect of soapwort extract on physical and sensory properties of sponge cakes and rheological properties of sponge cake batters

Soapwort extract yields relatively stable, soap-like foam in aqueous solution because of its saponin content. The objective of this study was to utilise the advantage of the high foam forming capacity of soapwort extract in the production of sponge cakes. Egg white proteins were partially replaced with soapwort extract in the sponge cake formulation. The effects of soapwort extract addition on the rheological and physical properties of cake batters and on the physical and sensory properties of sponge cakes were determined. Replacing egg white proteins with soapwort extract, up to 75% by weight, did not have any significant influence on the specific gravity of batters (p > 0.05). Addition of soapwort extract into the cake mixture did not influence the flow behaviour indices (n) of cake batters nor the consistency indices (K) of cake batters. In general, replacing egg white proteins with soapwort extracts (up to 75% by weight) did not alter physical properties of sponge cakes. Replacing egg white proteins with soapwort extract had no unfavourable influence on the sensory properties of sponge cakes. Indeed, sponge cakes formulated with soapwort extract (by replacing egg white proteins by 50% and 75% on weight basis) received significantly higher chewiness scores than did control cakes (p < 0.05). This study showed that egg white proteins could be partially replaced with soapwort extract in the formulation of sponge cakes.     

Effect of frozen storage conditions (temperature and length of storage) on microbiological and sensory quality of rustic crossbred beef at different states of ageing

The effect of frozen storage conditions on meat from 36 Morucha × Charolais crossbred yearlings was studied. Slices of M. Longissimus thoracis were randomly assigned to groups arising from the combination of experimental factors. These factors were: ageing extent (3 and 10 days), length of frozen storage (0, 30, 75 and 90 days) and temperature (−20 and −80 °C). Regarding microbiological counts, although values were acceptable in all cases, longer storage time and longer previous ageing extent provided higher phychrotrophic bacteria counts. As frozen storage period increased, colorimetric parameters L^∗, a^∗ and C^∗ decreased, but H^∗ increased. Regarding Warner–Braztler shear force and tenderness values, an interaction (p < 0.05) between frozen storage and post-mortem ageing resulted from larger differences between frozen storage periods at shorter ageing periods than those at longer ageing periods. Frozen storage for 90 days resulted in a reduction in water holding capacity, without differences in juiciness. No effect of freezing temperature was observed in any of the parameters studied.     

Quality and antioxidant property of green tea sponge cake

Green tea powder was used to substitute 0%, 10%, 20%, and 30% of wheat flour to make sponge cakes, called the control, GT10, GT20, and GT30, respectively. The viscosity and specific gravity in cake batter, and hardness, gumminess, chewiness, crumb a value, protein, total dietary fibre, ash, and various catechin content of baked cakes increased with increasing green tea levels whereas the volume, cohesiveness, adhesiveness, springiness, resilience, crust L, a, b and crumb L, b values of samples showed a reverse trend. No differences were found in all hedonic sensory results for control, GT10, and GT20 whereas GT30 were rated lower in all sensory results. Green tea cake contained a greater variety of catechins, and had good antioxidant activity, reducing power, scavenging ability on 1,1-diphenyl-2-picrylhydrazyl radicals and chelating ability on ferrous ions. Overall, green tea cake could be developed as a food with more effective antioxidant properties.     

Impact of pretreatment and freezing conditions on the microstructure of frozen carrots: Quantification and relation to texture loss

The textural quality of carrots subjected to pretreatments affecting the pectin structure in combination with different freezing conditions was studied. Carrot samples frozen under different conditions were extensively studied by light microscopy quantifying the freezing damage based on the analysis of different parameters (number, area, perimeter, and shape factor of tissue particles) associated with carrot tissue damage. The reduced texture loss of rapidly or cryogenically frozen carrots, compared to slowly frozen samples, was associated with the reduction in cell wall damage in the carrot tissue. In case no pretreatment was used, carrot texture was only slightly improved by using high-pressure shift freezing instead of slow freezing. Detailed analysis of the different steps involved showed that severe tissue damage occurred during the completion of the high-pressure freezing process at atmospheric pressure. However, tissue damage, and thus texture loss, of high-pressure frozen carrots could be minimized by applying pretreatments consisting of a thermal treatment at 60 °C and a high-pressure treatment at 300 MPa and 60 °C.     

Effect of freezing method and frozen storage duration on lamb sensory quality

This study assessed the effect of three freezing methods with three frozen storage durations (1, 3, and 6 months) on the sensory quality of lamb. Methods were: air blast freezer, freezing tunnel + air blast freezer, and nitrogen chamber + air blast freezer. Meat was frozen after 48 h of ageing (0-4 °C). Fresh meat (72 h ageing at 2-4 °C) was used as control. Sensory analyses (trained panel and consumer tests) were performed on loin chops (Longissimus lumborum) after 24 h of thawing. Results from the trained panel test showed that freezing (method and/or storage duration) had no significant effect. Consumers found that freezing affected sensory quality. Cluster analysis for overall acceptability divided the population into four classes with different preference patterns, and none of them showed a significant preference for fresh meat. The small differences between fresh and thawed meat shown in this study should not give consumers concerns about buying frozen meat or consuming thawed meat.     

Effect of hydrocolloids and emulsifiers on the rheological,microstructural and quality characteristics of eggless cake

Effect of hydrocolloids like Arabic (AR), guar (GR), xanthan (XN), carrageenan (CG) and hydroxypropylmethylcellulose (HPMC) in combination with emulsifiers such as glycerol monostearate (GMS) and sodium stearoyl-2-lactylate (SSL) on the rheological, microstructural and quality characteristics of eggless cake was studied. Addition of GR to wheat flour in the presence of SSL increased peak viscosity, while in the presence of GMS all hydrocolloids excepting XN increased the peak viscosity. The set back value decreased with the addition of hydrocolloids. Addition of hydrocolloids to wheat flour as well as in the presence of GMS and SSL increased the eggless cake batter viscosity, specific gravity, and XN showed the highest value. Among different hydrocolloids tried, only HPMC improved the eggless cake making characteristics of wheat flour. Use of HPMC increased the overall quality score of eggless cake with GMS to the maximum extent followed in decreasing order by CG and XN. Addition of all the hydrocolloids increased the overall quality of eggless cake with SSL and highest improvement was brought about by HPMC. Microstructure studies of eggless cake crumb with hydrocolloids showed that the starch granules appeared wrapped by XN and HPMC. In eggless cake with combination of HPMC and SSL the protein matrix appeared more uniform.     

浓缩乳清蛋白替代全蛋液对海绵蛋糕品质的影响

研究了以浓缩乳清蛋白替代全蛋液对海绵蛋糕品质的影响,分析了不同替代比例下海绵蛋糕的面糊比重、蛋糕比容、蛋糕硬度、弹性和咀嚼性的变化情况,并对蛋糕进行了感官评定。研究表明,在替代比例不超过50%时,得到面糊比重、蛋糕比容、充氮气密封包装保存60d后蛋糕的质构性能均接近采用全蛋液制作的蛋糕,感官评定结果表明,当替代比例为50%时蛋糕的品质最佳。由此可见,浓缩乳清蛋白部分替代全蛋液来制作海绵蛋糕是可行的。     

Effect of freezing rate on quality parameters of freeze dried soursop fruit pulp

The effect of freezing rate on the final moisture and ascorbic acid content, water solubility, wettability and color of freeze dried soursop fruit pulp treated with maltodextrin was studied. Different size ice crystals derived from distinct freezing rates origins diversity of product specific surface area that influence both water desorption and water dissolution, but in opposite manners. After a constant drying time of 6 h the moisture content of the dried samples was in the range of 8.68–13.09% being higher for higher values of freezing rate. An inverse linear dependence between initial freezing rate and final water solubility (85.75–81.51%) of freeze dried samples was also found. Faster freezing rates also affected the wetting time (0.36–1.26 min) because they produced decreasing in pore size and simultaneously increasing in capillary tortuosity of the final micro-structure of the dried samples. Freeze-dried powders were much brighter in color compared to the maltodextrin treated pulp. Among the freeze dried samples, those prepared with higher freezing rates were lighter in color.     

Effects of freezing and frozen storage on the microstructure and texture of ewe's milk cheese

Semi-hard ewe's milk cheeses, frozen immediately after manufacture either slowly at –35 °C or rapidly at –80 °C and stored at –20 °C for 4 months were studied for microstructural and textural characteristics during subsequent ripening. Two control groups were used to establish the effect of freezing: the fresh unfrozen cheese and cheese thawed immediately after freezing. Freezing proper did not result in any marked changes in the textural parameters of the cheeses, but considerable changes were found in slowly frozen cheeses after 4 months of frozen storage. Shear strength values were lower in all frozen and stored cheeses, particularly in cheese samples frozen slowly compared to those in the unfrozen control batch. This parameter and firmness values were significantly lower in both slowly and rapidly frozen cheeses at the completion of ripening. Ripening tended to offset differences in elasticity, noticeable in the cheeses during the first 30 days of ripening. Light microscopy and electron microscopy revealed small cracks and ruptures in the cheeses which could not be observed by the naked eye. More extensive damage to the cheese microstructure was found in slowly frozen cheese samples stored frozen for 4 months.     

Minimizing texture loss of frozen strawberries: effect of infusion with pectinmethylesterase and calcium combined with different freezing conditions and effect of subsequent storage/thawing conditions

Vacuum infusion (VI), freezing, frozen storage and thawing conditions were optimized in order to minimize the texture loss of frozen strawberries. Slow freezing caused severe loss in textural quality of the strawberries. This quality loss could not be prevented by the application of VI prior to slow freezing, or by the application of rapid, cryogenic or high-pressure shift freezing conditions on non-infused fruits. A remarkable texture improvement was noticed when infusion of pectinmethylesterase (PME) and calcium was combined with rapid or cryogenic freezing. The highly beneficial effect of PME/Ca-infusion followed by HPSF on the hardness retention of frozen strawberries was ascribed to the combined effect of the infused PME (53% reduction in degree of esterification (DE) of the strawberry pectin) and the high degree of supercooling during HPSF. During frozen storage, textural quality of PME/Ca-infused high-pressure frozen strawberries was maintained at temperatures below −8 °C, whereas the texture of PME/Ca-infused strawberries frozen under cryogenic freezing conditions was only preserved at temperatures below −18 °C. Thawing at room temperature seemed to be an appropriate method to thaw strawberries. Fast thawing by high-pressure induced thawing (HPIT) did not prevent textural quality loss of frozenstrawberries.     

冻结和解冻过程对水产品品质的影响

冻结是水产品保鲜的一种有效的方法,冻结后的水产品一般会进行冻藏。影响冻品质量的因素很多,主要有冻结速率、冻藏温度、解冻速率、冻藏中温度波动、冻结-解冻循环次数等。本文在简要介绍食品的冻结解冻方法的基础上,综述了冻结解冻过程对水产品物理、化学特性的影响。     

Effect of freezing method and frozen storage duration on instrumental quality of lamb throughout display

This study evaluated the effect of freezing method (FM) (air blast freezer, freezing tunnel, or nitrogen chamber) and frozen storage duration (FSD) (1, 3, or 6 months) on the instrumental measurements of quality of thawed lamb, aged for a total of 72 h, throughout a 10-d display period, compared to the quality of fresh meat. pH, colour, lipid oxidation, thawing, and cooking losses in Longissimus thoracis and lumborum muscle, were determined following standard methods. FM affected yellowness, FSD redness and thawing losses, and both affected oxidation (increased as freezing rate decreased and/or as storage duration increased). When compared with fresh meat, the main differences appeared on oxidation (where a significant interaction between treatment (3FM × 3FSD + fresh meat) with display duration was detected), and on total losses (thaw + cook losses). Oxidation was lower in fresh meat, but values were not significantly different from those stored frozen for 1 month. Fresh meat had smaller total losses than did thawed meat, but losses were not significantly different from meat frozen in the freezing tunnel and stored frozen for 1 month. Display duration had a greater effect on instrumental quality parameters than did FM or FSD. pH, b*, and oxidation increased, and L* and a* decreased with an increase in the number of days on display. In conclusion, neither freezing method nor frozen storage up to 6 months influenced extensively the properties of lamb when instrumental measurements of quality were measured in meat that had been displayed for 1 d after thawing. The small deterioration shown in this study should not give consumers concerns about frozen meat.     

鱼精蛋白对延长鱼糕制品有效保存期的作用

本文用鱼精蛋白、苯甲酸钠和山梨酸钾分别添加在鱼糕制品中，并于12℃和24℃条件下保存，观察其保存效果。结果表明：添加0．8％鱼精蛋白的鱼糕在12℃和24℃的有效保存期分别为7d和5d，达到添加0．3％苯甲酸钠和0．2％山梨酸钾的效果。