|a英文題名:Microencapsulation of lactic acid bacteria with high-amylose corn starch
|a傳統醃漬食品多為植物性來源，長時間發酵的食品菌相複雜，其醃漬液中可能存在酵母菌，醋酸菌，乳酸菌，腐敗菌以及黴菌。本實驗利用MRS、Rogosa SL和M17 agar 作為選擇性培養基篩選出乳酸菌，探討以高直鏈玉米澱粉作為益生質，進行乳酸菌為膠囊產品之製備。將高直鏈澱粉玉米澱粉 Hylon V（HV）與Hylon VII（HVII）作為抗性澱粉之來源，測定植物性乳酸菌吸附抗性澱粉之能力。配製調整培養基HV或HVII完全取代Lactobacilli MRS broth之碳源，並從98株乳酸菌中篩選出利用和吸附抗性澱粉能力較高之菌株共五株，分別為PM133，PM135，PM136，PM166，PM212，其中 PM212的外型為桿菌和其他四株皆為球菌。本研究利用噴霧乾燥技術進行乳酸菌微膠囊化。載體溶液含30% 載體（18%麥芽糊精和12% 阿拉伯樹膠），1%（w/w）細胞培養，1%（w/w）高直鏈玉米澱粉（HV或HVII）。設定噴霧乾燥機之入口溫度120℃，出口溫度60℃。測定乳酸菌微膠囊之菌體包埋率、粒徑分布、水活性、水分含量、模擬胃液試驗、模擬胃液試驗後膽鹽試驗及不同儲存溫度之菌數變化情形。結果顯示乳酸菌微膠囊之包埋率皆達81% 以上其菌數約108-1010 CFU /g，水活性低於0.28，水含量約占2-3％，平均粒徑分布約14-29 m。乳酸菌本身經模擬胃液試驗後發現PM133和PM135之耐酸能力較低經微膠囊化後可提升耐酸程度，且維持菌株於耐酸後耐膽鹽之菌數量。經過微膠囊化後之菌株的包埋率以球菌優於桿狀菌。乳酸菌微膠囊儲存於避光條件下比未避光條件更能維持菌數。產品儲存於 -20℃之活菌數高於4℃，而4℃則優於25℃。於 -20℃ 儲存60天後其產品的活菌數約108-1010 CFU /g、水活性0.2-0.3、含水量2-4% 及其模擬胃液後接續進行膽鹽試驗之活菌數為107-108 CFU /g。綜合上述，乳酸菌微膠囊產品儲存期間應避光，且低溫儲存環境更有利於維持產品之穩定。添加1% 高直鏈玉米澱粉製備乳酸菌微膠囊有助於乳酸菌菌株於儲存期間、模擬胃腸系統中之活菌數。|uMost traditional food sources are from plants and it contains microfloras, like yeast, acetic acid bacteria, lactic acid bacteria (LAB), spoilage bacteria and mold may ferment food for long time. In this study, MRS, Rogosa SL, and M17 agar as the selective medium and resistant starch (RS) as prebiotic of LAB, used to prepare microencapsulate LAB products. The high-amylose corn starch, i.e. Hylon V (HV) and Hylon VII (HVII) were be RS, to determine adhesive ability with LAB isolated from 98 strains of plant source. MRS modified medium contained HV or HVII as the carbon source were used to determine the highest availability and adhesion (%) of five strains, PM133, PM135, PM136, PM166, and PM212, respectively, in this five strains PM212 is rod and remaining four are cocci. Spray drying technique to microencapsulated LAB. Carrier solution contained 30% carrier (18% maltodextrin and 12% gum arabic), 1% (w/w) cell culture, and 1% (w/w) RS (HV or HVII). The outlet temperature setting was 120℃ and the outlet temperature setting was 60℃ of the spray drying conditions. To measured parameters like encapsulation yield, particle size, and to analysis water activity, moisture content, simulated gastric fluid test, bile salts test after simulated gastric fluid test, and varied the number of bacteria in different storage temperature. The results demonstrated that microencapsulated LAB yield were more than 81% with bacterial counts 108-1010 CFU/g, water activity wereless than 0.28, moisture content counts 2-3%, the average particle size were about 14-29 m. PM133 and PM135 strains were improved their poor survivability after microencapsulated in simulated gastric juice. The encapsulation yield of coccus-type was higher than rod-type. The acid and bile resistant ability and strain counts stability were more in microencapsulated strains than unmicroencpasulated. The viability in dark storage conditions was better than light storage conditions. To stored at -20℃ was better than 4℃, and Stored 4℃ was better than 25℃. The microencapsulated LAB could be stored at -20℃ for 60 days, with the counts of viable cells were about 108-1010 CFU/g, water activity were 0.2-0.3, moisture content were 2-4%, and the counts of viable cells after simulated gastric juice and bile salt test were 107-108 CFU/g. In conclusion, to stored microencapsulated LAB in the dark and -20℃ was better. Microencapsulation of LAB with 1% high-amylose corn starch could improve the survivability of LAB strains during storage and in simulated gastroenteric system.
|aMicroencapsulation of lactic acid bacteria with high-amylose corn starch