Carboni Angela Daniela, Gómez-Zavaglia Andrea, Puppo Maria Cecilia, Salinas María Victoria
Centro de Investigación y Desarrollo en Criotecnología de Alimentos (CIDCA), Facultad de Ciencias Exactas, Universidad Nacional de La Plata (UNLP)-CONICET, 47 y 116, La Plata RA1900, Argentina.
Facultad de Ciencias Agrarias y Forestales, Universidad Nacional de La Plata, 60 y 122, La Plata RA1900, Argentina.
Foods. 2022 Jun 24;11(13):1866. doi: 10.3390/foods11131866.
Bread is a popular food that is widely consumed worldwide but has a short shelf life. Besides that, when incorporating prebiotics and calcium, aging mechanisms accelerate, further shortening the shelf-life. The objective of this work was to evaluate the effect of freezing storage on the rheological (loss tangent, tan δ) and thermal (glass transition temperature, Tg) properties of unfrozen dough, the fermentation times (tf), and the baking quality of wheat bread fortified with calcium and inulin. Formulations studied included wheat flour (control-C), flour with 1800 ppm Ca (calcium carbonate-CA, calcium citrate-CI or calcium lactate-LA), and flour with 2400 ppm Ca and 12% inulin (calcium carbonate-CA-In, calcium citrate-CI-In or calcium lactate-LA-In). Doughs were stored at −18 °C for 1, 7, 30 and 60 days. After storage, the rheological (oscillatory rheometry and texture profile analysis) and thermomechanical properties of the thawed doughs were measured. The quality parameters of breads determined consisted of specific volume (Vs), color, moisture, firmness, elasticity, and alveoli size characterization. Dough freezing neither changed viscoelasticity (tan δ) nor decreased hardness and adhesiveness up to the values observed for fresh wheat dough. The Tg of dough with calcium carbonate increased, while for samples with organic calcium salts, it (citrate and lactate) decreased. The tf of thawed dough significantly increased. The Vs of all breads did not change during the first 30 days but decreased after freezing the dough for 60 days (p < 0.05), probably due to the death of the yeasts. Crumb moisture decreased over time, and in all cases crumb C had the highest moisture content, suggesting a dehydration effect of the calcium salt. The firmness of CA, LA and C crumbs were similar and higher than that of CI (p < 0.05), suggesting a destabilizing effect of CI anion on gluten proteins. Inulin contributed to the depreciation of bread quality, mainly at 60 days of dough freezing storage. It can be concluded that during freezing storage, calcium improves the dynamic elasticity of the dough, although under extreme conditions it generates loaves of smaller volume. Principal component analysis (PCA) explained 66.5% of total variance. Principal component 1 (PC1) was associated with dough properties, and accounted for 44.8% of the total variance. In turn, PC2 was mainly related to baking quality parameters (fermentation time, browning index, firmness and springiness of crumbs), and explained 21.7% of the total variance. Fortification with calcium citrate should be recommended for dough freezing, as breads with softer crumbs were obtained under such conditions.
面包是一种广受欢迎的食品，在全球范围内被广泛食用，但保质期较短。除此之外，当添加益生元和钙时，老化机制会加速，进一步缩短保质期。这项工作的目的是评估冷冻储存对未冷冻面团的流变学性质（损耗角正切，tan δ）和热学性质（玻璃化转变温度，Tg）、发酵时间（tf）以及添加钙和菊粉的小麦面包烘焙品质的影响。所研究的配方包括小麦粉（对照 - C）、含有1800 ppm钙的面粉（碳酸钙 - CA、柠檬酸钙 - CI或乳酸钙 - LA），以及含有2400 ppm钙和12%菊粉的面粉（碳酸钙 - CA - In、柠檬酸钙 - CI - In或乳酸钙 - LA - In）。面团在 - 18°C下储存1、7、30和60天。储存后，测量解冻后面团的流变学性质（振荡流变学和质地剖面分析）和热机械性质。所测定的面包品质参数包括比容（Vs）、颜色、水分、硬度、弹性和气孔大小表征。面团冷冻既未改变粘弹性（tan δ），也未使硬度和粘性降低至新鲜小麦面团所观察到的值以下。含有碳酸钙的面团的Tg升高，而含有有机钙盐（柠檬酸盐和乳酸盐）的样品的Tg降低。解冻后面团的tf显著增加。所有面包的Vs在最初30天内未发生变化，但在面团冷冻60天后降低（p < 0.05），这可能是由于酵母死亡所致。面包心水分随时间减少，在所有情况下，面包心C的水分含量最高，这表明钙盐具有脱水作用。CA、LA和C面包心的硬度相似且高于CI（p < 0.05），这表明CI阴离子对面筋蛋白有去稳定作用。菊粉主要在面团冷冻储存60天时导致面包品质下降。可以得出结论，在冷冻储存期间，钙可改善面团的动态弹性，尽管在极端条件下它会使面包体积变小。主成分分析（PCA）解释了总方差中的66.5%。主成分1（PC1）与面团性质相关，占总方差的44.8%。相应地，PC2主要与烘焙品质参数（发酵时间、褐变指数、面包心硬度和弹性）相关，并解释了总方差的21.7%。对于面团冷冻，建议添加柠檬酸钙，因为在这种条件下可获得面包心较软的面包。
