| Summary: | 碩士 === 國立屏東科技大學 === 食品科學系所 === 104 === Being high in nutritional value and low in calories, sprouts have become more and more popular because of the health conscious consumers. However, the respiration continues after sprouts being harvested, which makes their shelf-life short, normally within 1 week. The imbalance between the sprout production and marketing raised a new issue on how to increase the sprout commercialvalue.Djulis sprouts are less well-known than their seeds, however their nutrition values and functional ingredientsare better than seeds.
In this study,the objectives were divided into three parts.First to investigate the efficiency of different postharvest treatment in broccoli sprouts using Taguchi’s method experimental design, to determinethe best condition of each factor and apply to Djulis sprouts.The factors were ClO2 (antibacterial ability),GABA(reduce chilling injury), CMC(water holding capacity) and MAP(respiration inhibition), and all of the treatments were measured for their shelf-life, their antioxidant activity changes, and changes incolor ofDjulis sprouts. Second,Djulis sprouts werecompared with the common sprout such as quinoa sprout, buckwheat sprout, broccoli sprout and red cabbage sproutto test theeffects of different drying methods (freeze dry,oven dry and vacuum dry) were also discussed.
The results showed that best time to harvest was seventh day, the optimumextraction of Brassicaceaesprout was 4 hour, 1:40(g/ml),and ethanol 60%. The best postharvest treatmentsfor Djulis sprouts were, ClO2, GABA, CMC, MAP (CGCM). GABA indicated better result than vit C in this study, so GABA is suggested to replace vit C in the future study. All of the treatments of Djulis sprouts were able to extend the shelf-life until 10 days. CGCM treatment was wight loss 28%, total phenol content 2813 mg/100g, retention 86%.CK treatment was wight loss 54%, total phenol content 2521 mg/100g, retention 77%, it was no commercialvalue in 8 days.
Freeze drying method was proven to have better pigment and antioxidant activity than oven and vacuum drying no matter the types of sprout were.For example, total phenol content of Djulis sprouts after freeze drying was 3919 mg/100g, oven drying 2956 mg/100g, vacuum drying 3358 mg/100g. Analysis of sinigrin broccoli sprout after freezedrying was 34.75 mg/100g, oven drying 21.31 mg/100g, vacuum drying 25.92 mg/100g. So the best drying method was freeze dry better than vacuum dry better than oven dry.
The last stage was to produce a product, sprout energy soup, from the best drying method (freeze drying method) by using Taguchi’s method based on sensory evaluation. The quality analysis of sprout energy soup total phenol content was 1125 mg/100g, flavonoid 24.17 mg/100g, FRAP 389.42 μm/L, DPPH scavenging 90%. This product can be compared with commercial product, and to study about its storage stability, at 25℃ can be stored for 60.22 weeks
|
|---|
