Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/51304
標題: Quality Evaluation of Lactic Acid Bacteria Bread
乳酸菌麵包品質之評估
作者: Tzeng, Yeong-Ming
曾永明
關鍵字: 乳酸菌;lactic acid bacteria;土司麵包;toast bread
出版社: 食品暨應用生物科技學系
摘要: 
Abstract
The key technique of bread production is the improvement of flavor and storage time and the addition of lactic acid bacteria (LAB) to bread during the manufacturing process would help. In this study first screened LAB with the ability to leaven the sourdough and produce good flavor. Among the 16 tested strains, Lactobacillus delbrueckii delbrueckii (LDD) produced the most acidity and Pediococcus acidilactici (PA) produced the best flavor. We then used these two strains in toast making. LDD and PA were added into sourdough which was made to toast, and the proximate composition, physical parameters, taste quality, volatile components, bioactive components and sensory quality of toast were analyzed.
Experiment results indicated that the lightness of the three toasts were in the descending order of LDD toast(71.20)>white toast(69.97)> PA toast(68.98). X-ray diffraction revealed that the peak strength of the three toasts increased during the storage time. In a six-day storage experiment at 25℃, the hardness of the three toasts increased, while hardness, cohesiveness, gumminess, chewiness and resilience decreased with time. The LDD toast was the most abundant in nucleotides content (1.95 μg/g), following by white toast (1.11 μg/g) and PA toast (0.97 μg/g). Also, the LDD toast contained the most organic acid (4.07 mg/g) and PA toast (4.35 mg/g) following by white toast (3.10 mg/g). LDD toast contained the most kinds and quantity of aromas.
In the six-day storage experiment, the total plate count of PA toast (3.20 log CFU/g) and LDD toast (46 log CFU/g) were significantly lower than white toast (7.85 log CFU/g) (p<0.05). With regard to the hedonic scores in sensory evaluation, LDD toast and PA toast were more accepted than white toast in flavor and mouth feel.
In a summary, the addition of LDD to toast enhanced the palatable taste and sweet taste, and thus improved the flavor and nutritional value of toast.

中文摘要
目前麵包製作技術的訴求,主要在於如何增加其風味及延長儲藏時間,而添加乳酸菌於土司麵包製作即可以達到此目的。本研究先從16株乳酸菌中,篩選出能使麵包膨脹及風味佳之乳酸菌,最後選定產酸最高的Lactobacillus delbrueckii delbrueckii (LDD)及產生風味最佳的Pediococcus acidilactici (PA)兩株菌,進行土司麵包實驗。特以乳酸菌添加入麵糰中,製成乳酸菌土司,並以白土司作為對照組,進行一般成分、物理性質、呈味品質、香氣成分、儲藏性質及感官品評之分析。
實驗結果顯示,三種土司的白度依序為LDD土司(71.20)>、白土司(69.97)> 、PA土司(68.98)。X-射線繞射分析發現三種土司之繞射峰的強度,會隨著儲藏時間增加而逐漸增強。三種土司於25℃下儲藏6天後,進行質地剖析之結果顯示隨著儲藏時間的增加,硬度有增加的趨勢,而彈性、凝聚度、膠性度、咀嚼度及恢復力則隨著時間的延長而降低。在呈味品質上, 三種土司的核苷酸含量以LDD土司最高(1.95 μg/g),白土司次之(1.11 μg/g),PA土司最低(0.97 μg/g)。在有機酸含量分析方面,LDD土司(4.07 mg/g)和PA土司(4.35 mg/g)比白土司(3.10 mg/g)高。在香氣分析中,以LDD土司之香氣分析組成(53種香氣化合物)最多且含量最高。
儲藏六天後土司總生菌數, PA土司(3.20 log CFU/g)及LDD土司(3.46 log CFU/g)的總生菌數明顯比白土司(7.85 log CFU/g)低(p<0.05)。在感官品評之消費者喜好性分析上,LDD土司與PA土司在風味及口感上都比白土司有較高的接受度。
綜合以上結果,顯示LDD乳酸菌的添加可明顯提高土司中的鮮味及甜味,進而提高土司的風味與營養價值及延長儲藏時間。
URI: http://hdl.handle.net/11455/51304
Appears in Collections:食品暨應用生物科技學系

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