Graduate School of Life Sciences and Biotechnology, Korea University, Anam-dong, Sungbuk-ku, Seoul, Republic of Korea.
Int J Food Microbiol. 2013 Jan 1;160(3):260-6. doi: 10.1016/j.ijfoodmicro.2012.10.020. Epub 2012 Nov 12.
A study was done to determine the potential use of plant extracts to inhibit the growth of Bacillus cereus in reconstituted infant rice cereal. A total of 2116 extracts were screened for inhibitory activity against B. cereus using an agar well diffusion assay. The minimal inhibitory concentrations (MIC) and minimal lethal concentrations (MLC) of 14 promising extracts in tryptic soy broth (TSB) were determined. Dryopteris erythrosora (autumn fern) root extract showed the lowest MIC (0.0156 mg/ml), followed by Siegesbeckia glabrescens (Siegesbeckia herb) leaf (0.0313 mg/ml), Morus alba (white mulberry) cortex (0.0313 mg/ml), Carex pumila (sand sedge) root (0.0625 mg/ml), and Citrus paradisi (grapefruit) seed (0.0625 mg/ml) extracts. The order of MLCs of extracts was D. erythrosora root (0.0156 mg/ml)<S. glabrescens leaf (0.0313 mg/ml)<M. alba cortex (0.0625 mg/ml)=Siegesbeckia pubescens aerial part (0.0625 mg/ml)<C. paradisi seed (0.1250 mg/ml). The combined inhibitory effects of extracts against B. cereus in TSB were determined using a checkerboard assay. A combination of D. erythrosora and C. pumila extracts showed a partial synergistic inhibition, with a fractional inhibitory concentration index (FICI) of 0.75. Single and combined inhibitory activities of selected plant extracts against B. cereus in reconstituted infant rice cereal were investigated. The MICs of S. glabrescens, M. alba, D. erythrosora, and C. pumila extracts against B. cereus were 1.0, 2.0, 2.0, and 8.0mg/ml, respectively. A combination of D. erythrosora (1.00 mg/ml) and C. pumila (1.00 mg/ml) extracts showed a partial synergistic effect (FICI 0.63) in inhibiting the growth of B. cereus. Results indicate that by combining extracts, the amounts of D. erythrosora and C. pumila extracts can be reduced by 50% and 87.5%, respectively, compared with individual extracts, and give similar inhibitory activity in reconstituted infant rice cereal. Sensory evaluation showed that supplementing reconstituted infant rice cereal with plant extracts reduces sensorial quality. These observations will be useful when developing and applying interventions using natural plant extracts to inhibit B. cereus in foods.
进行了一项研究，以确定植物提取物抑制重组婴儿米粉中蜡样芽胞杆菌生长的潜力。使用琼脂孔扩散法筛选了 2116 种提取物，以检测其对蜡样芽胞杆菌的抑制活性。在胰蛋白酶大豆肉汤（TSB）中测定了 14 种有前途的提取物的最小抑菌浓度（MIC）和最小致死浓度（MLC）。紫萁（秋季蕨类植物）根提取物的 MIC 最低（0.0156mg/ml），其次是筋骨草（筋骨草属植物）叶（0.0313mg/ml）、桑白皮（白桑）（0.0313mg/ml）、地肤（地肤）根（0.0625mg/ml）和葡萄柚（葡萄柚）籽（0.0625mg/ml）提取物。提取物 MLC 的顺序为紫萁根（0.0156mg/ml）<筋骨草叶（0.0313mg/ml）<桑白皮（0.0625mg/ml）=筋骨草地上部分（0.0625mg/ml）<葡萄柚籽（0.1250mg/ml）。使用棋盘试验确定提取物在 TSB 中对蜡样芽胞杆菌的联合抑制作用。紫萁和地肤提取物的组合表现出部分协同抑制作用，部分抑菌浓度指数（FICI）为 0.75。研究了选定的植物提取物在重组婴儿米粉中对蜡样芽胞杆菌的单一和联合抑制活性。筋骨草、桑白皮、紫萁和地肤提取物对蜡样芽胞杆菌的 MIC 分别为 1.0、2.0、2.0 和 8.0mg/ml。紫萁（1.00mg/ml）和地肤（1.00mg/ml）提取物的组合对蜡样芽胞杆菌的生长表现出部分协同作用（FICI 0.63）。结果表明，与单独使用提取物相比，组合使用紫萁和地肤提取物可将提取物的用量分别减少 50%和 87.5%，在重组婴儿米粉中具有相似的抑制活性。感官评价表明，在重组婴儿米粉中添加植物提取物会降低感官质量。在开发和应用使用天然植物提取物抑制食品中蜡样芽胞杆菌的干预措施时，这些观察结果将非常有用。
