玉米鬚粉添加及模具溫度對膨發玉米點心品質及抗氧化能力之影響

玉米 (Zea mays L.) 是世界上主要的穀物之一，而在加工玉米成為玉米碎時會產生許多副產物，其中玉米鬚(Corn Silk, CS)為主要的副產物之一。CS為玉米生長過程中所產生的絲狀物質，具有許多對人體有益處的能力，包括抗氧化、抗發炎、抗腫瘤、抗糖尿病和抗肥胖等。此外，CS中含有許多對人體健康有顯著影響的生物活性成分，如多醣、黃酮、生物鹼、皂苷和氨基酸。其中玉米鬚多醣(Corn Silk Polysaccharide, CSP)已被證明是一種潛在的治療劑，具有抗糖尿病、抗腫瘤、抗疲勞、抗氧化和抗肥胖等積極作用。食品擠壓是一種能源有效利用且高產量的加工工藝，是一種高溫短時 (HTST) 加工，可減少食品營養成分被破壞以保持成品的品質。本研究以特定玉米鬚粉添加量（0、2.5、5、7.5、10%）、特定模具溫度（100、110、120℃）來膨發擠壓玉米碎生產具有抗氧化能力的玉米點心。特別探討玉米鬚粉及擠壓機模具溫度對膨發玉米點心的物理性質〔色澤、質地、徑向膨發率、吸水性指標（WAI）及水溶性指標（WSI）〕、抗氧化能力（總酚類化合物含量、總類黃酮含量、DPPH自由基清除能力、還原能力）及感官品評特性的影響。由實驗結果得知，不同玉米鬚粉添加量、不同模具溫度皆會影響擠出物的物理特性，在相同模具溫度下，隨著玉米鬚粉添加量增加，其擠出物的L*、徑向膨發率、WSI均有顯著地（p<0.05）減少，且擠出物的外觀也呈現不規則形狀。在抗氧化能力方面，在相同玉米鬚粉添加量下，隨著模具溫度上升，擠出物的總酚類化合物含量、總類黃酮化合物含量、DPPH自由基清除能力及還原能力也隨之上升。其中在玉米鬚粉添加量為10%和模具溫度120℃的條件下，擠出物有最高的抗氧化能力，視為本研究所獲得膨發玉米點心，總酚類化合物含量1297.15 mg GAE/100 g d.m、DPPH自由基清除能力86.27%、還原能力0.15以及總類黃酮含量1887.50 mg GAE/100 g d.m。

關鍵字

膨發點心；玉米；玉米鬚；抗氧化；擠壓

並列摘要

(Zea mays L.) is one of the major cereals in the world. When processing corn into corn grits, many by-products are produced, among which corn silk (CS) is one of the main by-products. CS is a filamentous substance produced during the growth of corn and has many biological activities, including antioxidant, anti-inflammatory, anti-tumor, anti-diabetic and anti-obesity. In addition, CS contains many bioactive ingredients that have significant effects on human health, such as polysaccharides, flavonoids, alkaloids, saponins, and amino acids. Among them, Corn Silk Polysaccharide (CSP) has been proven to be a potential therapeutic agent with positive effects such as anti-diabetic, anti-tumor, anti-fatigue, antioxidant and anti-obesity. Food extrusion is an energy-efficient and high-throughput processing process. It is a high-temperature short-time (HTST) process that reduces the destruction of food nutrients to maintain the quality of the finished product. In this study , specific amount of corn silk powder addition amount (0, 2.5, 5, 7.5, 10%) and specific die temperatures (100, 110, 120°C) were to used extrude corn grits to produce bioactive corn snacks. Specially explore the effects of corn silk powder and extruder die temperature on the physical properties of expand corn snacks (color, texture, radial expansion rate, water absorption index (WAI) and water solubility index (WSI)), antioxidant capacity (total phenolic compound content, total flavonoid content, DPPH free radical scavenging ability, reducing ability) and sensory evaluation. It is known from the experimental results that changing corn silk powder addition and the die temperature would affect the physical properties of the extrudate. At the same die temperature, increasing the corn silk powder addition, the L* and radial expansion rate and WSI of the extrudate were significantly (p<0.05) reduced, and the appearance of extrudates also showed irregular shaper. In terms of antioxidant capacity, at the same corn silk powder addition, increasing the die temperature, the total phenolic compound content, total flavonoid content, DPPH free radical scavenging ability and reducing ability of extrudates also were increased. Among them, when the addition amount of corn silk powder is 10% and the mold temperature is 120°C, the extrudate has the highest antioxidant capacity and is regarded as the puffed corn snack obtained in this study. The total phenolic compound content is 1297.15 mg GAE/100 g d.m, DPPH free radical scavenging capacity 86.27%, reducing capacity 0.15 and total flavonoid content 1887.50 mg GAE/100 g d.m.