Lee Ga-Yang, Jung Min-Jeong, Kim Byoung-Mok, Jun Joon-Young
Food Convergence Research Division, Korea Food Research Institute, Wanju 55365, Republic of Korea.
Foods. 2023 Dec 25;13(1):74. doi: 10.3390/foods13010074.
The amount of processed by-products such as crab shells is increasing, but industrial utilization is insufficient. In our previous study, crab shell extract (CSE) acted as a coagulant for tofu manufacturing. This study aimed to reduce freeze-dried (FD) tofu breakdown by improving its physical properties through adding sodium alginate (SA). FD state in tofu helps increase storage and availability, but FD tofu frequently fractures during processing, which is a concern for manufacturers. Tofu samples were prepared with either crab shell extract (CSE) or MgCl, and SA, and freeze-dried. In the yields of FD tofu samples, there were no significant differences ( < 0.05). The brokenness of FD tofu samples was lower in CSE than in MgCl and was significantly reduced by SA in both tofu samples, which was affected by hardness. The water-holding capacity decreased after freeze-drying, and CSE reduced this decrease, regardless of SA addition. The microstructures differed depending on the coagulant and were dense upon SA addition. The FD tofu was packed into a multilayer film and stored at 25 °C or 45 °C for 6 months to investigate storage stability. During the storage, brokenness was unchanged in all tofu samples, indicating that they maintained their original structure. There were no significant differences in the volatile base nitrogen and thiobarbituric acid values according to the coagulant type and SA addition ( < 0.05). In conclusion, SA reduced FD tofu breakdown by improving the network structure, which may help increase FD tofu quality and decrease economic loss.
蟹壳等加工副产品的产量在增加，但工业利用率不足。在我们之前的研究中，蟹壳提取物（CSE）可作为豆腐生产的凝固剂。本研究旨在通过添加海藻酸钠（SA）改善其物理性质，以减少冷冻干燥（FD）豆腐的破碎。豆腐的FD状态有助于提高储存性和可用性，但FD豆腐在加工过程中经常破碎，这是制造商所担心的问题。用蟹壳提取物（CSE）或MgCl以及SA制备豆腐样品，并进行冷冻干燥。FD豆腐样品的产率没有显著差异（<0.05）。CSE处理的FD豆腐样品的破碎率低于MgCl处理的，并且SA在两种豆腐样品中均显著降低了破碎率，这受到硬度的影响。冷冻干燥后持水能力下降，无论是否添加SA，CSE都减少了这种下降。微观结构因凝固剂而异，添加SA后结构致密。将FD豆腐包装在多层薄膜中，在25℃或45℃下储存6个月以研究储存稳定性。在储存期间，所有豆腐样品的破碎率均未改变，表明它们保持了原来的结构。根据凝固剂类型和SA添加情况，挥发性盐基氮和硫代巴比妥酸值没有显著差异（<0.05）。总之，SA通过改善网络结构减少了FD豆腐的破碎，这可能有助于提高FD豆腐的质量并减少经济损失。
