Quintana Gabriel, Gerbino Esteban, Gómez-Zavaglia Andrea
Center for Research and Development in Food Cryotechnology (CCT-CONICET La Plata)Buenos Aires, Argentina.
Front Microbiol. 2017 Apr 12;8:641. doi: 10.3389/fmicb.2017.00641. eCollection 2017.
Okara is a nutritionally valuable by-product produced in large quantities as result of soymilk elaboration. This work proposes its use as both culture and dehydration medium during freeze-drying, spray-drying, and storage of CIDCA 83114. Whole and defatted okara were employed as culture media for CIDCA 83114. The growth kinetics were followed by plate counting and compared with those of bacteria grown in MRS broth (control). No significant differences in plate counting were observed in the three media. The fatty acid composition of bacteria grown in whole and defatted okara showed a noticeable increase in the unsaturated/saturated (U/S) fatty acid ratio, with regard to bacteria grown in MRS. This change was mainly due to the increase in polyunsaturated fatty acids, namely C18:2. For dehydration assays, cultures in the stationary phase were neutralized and freeze-dried (with or without the addition of 250 mM sucrose) or spray-dried. Bacteria were plate counted immediately after freeze-drying or spray-drying and during storage at 4°C for 90 days. Freeze-drying in whole okara conducted to the highest bacterial recovery. Regarding storage, spray-dried bacteria previously grown in whole and defatted okara showed higher plate counts than those grown in MRS. On the contrary, freeze-dried bacteria previously grown in all the three culture media were those with the lowest plate counts. The addition of sucrose to the dehydration media improved their recovery. The higher recovery of microorganisms grown in okara after freeze-drying and spray-drying processes and during storage was ascribed to both the presence of fiber and proteins in the dehydration media, and the increase in U/S fatty acids ratio in bacterial membranes. The obtained results support for the first time the use of okara as an innovative matrix to deliver . Considering that okara is an agro-waste obtained in large quantities, these results represent an innovative strategy to add it value, providing a symbiotic ingredient with promising industrial applications in the development of novel functional foods and feeds.
豆渣是豆浆制作过程中大量产生的具有营养价值的副产品。本研究提出将其用作CIDCA 83114冻干、喷雾干燥及储存过程中的培养基和脱水介质。使用全脂和脱脂豆渣作为CIDCA 83114的培养基。通过平板计数跟踪生长动力学，并与在MRS肉汤（对照）中生长的细菌进行比较。在三种培养基中平板计数未观察到显著差异。与在MRS中生长的细菌相比，在全脂和脱脂豆渣中生长的细菌的脂肪酸组成显示不饱和/饱和（U/S）脂肪酸比率显著增加。这种变化主要是由于多不饱和脂肪酸（即C18:2）的增加。对于脱水试验，将稳定期的培养物中和后进行冻干（添加或不添加250 mM蔗糖）或喷雾干燥。冻干或喷雾干燥后以及在4℃储存90天期间立即对细菌进行平板计数。在全脂豆渣中进行冻干可实现最高的细菌回收率。关于储存，先前在全脂和脱脂豆渣中生长的喷雾干燥细菌的平板计数高于在MRS中生长的细菌。相反，先前在所有三种培养基中生长的冻干细菌的平板计数最低。向脱水介质中添加蔗糖提高了它们的回收率。冻干和喷雾干燥过程后以及储存期间在豆渣中生长的微生物回收率较高归因于脱水介质中纤维和蛋白质的存在以及细菌膜中U/S脂肪酸比率的增加。所获得的结果首次支持将豆渣用作一种创新的载体。鉴于豆渣是大量获得的农业废弃物，这些结果代表了一种为其增值的创新策略，提供了一种在新型功能性食品和饲料开发中具有广阔工业应用前景的共生成分。
