酪梨（Persea americana）油作為冰淇淋中的脂肪替代品

Avocado (Persea americana) oil as fat replacement in ice cream

諾希沙(Nosisa Amanda Dlamini)

指導教授 ： 郭嘉信

國立屏東科技大學/國際學院/食品科學國際碩士學位學程/碩士(2018年)

https://doi.org/10.6346/THE.NPUST.FS.018.2018.E11

摘要

冰淇淋是世界上最受歡迎的冷凍甜點，它含有高含量的飽和脂肪和膽固醇，可能導致相關疾病。酪梨油含有大量的不飽和脂肪酸，實驗證明使用不飽和脂肪酸代替乳脂可以降低心血管疾病的風險。史瓦帝尼(原史瓦濟蘭)豐富的酪梨產量，將其運用到冷凍甜點上，同時也減少飽和脂肪的使用。這項研究主要目的是用酪梨油製作冰淇淋，用不同比例的酪梨油脫脂奶粉（Msnf）取代乳脂。分別使用乳脂與酪梨油製作脂肪含量15％的冰淇淋。透過乳脂（MIC）與酪梨油為基底的冰淇淋樣本H0（10% Msnf）、H1（20% Msnf）、H2（25% Msnf）和H3（40% Msnf），比較兩者的理化性質研究、感官分析與消費者接受度。冰淇淋的理化性質分析包括pH值、可滴定酸度、融化特性和水分含量。感官分析採前測方式進行，10名參與者以9分制喜好程度量表於外觀，口味，氣味，質地和整體接受度進行評分。接著42名參與者於感官分析初步測試結果加以描述9分制喜好程度量表上的每一個屬性。研究結果顯示MIC的pH值為6.52，可滴定酸度為0.17%。酪梨油製成的冰淇淋pH值範圍為6.46-6.49，可滴定酸度範圍為0.175-0.21%。酪梨油樣品隨著脫脂奶粉的增加顯示其pH值降低，並且融化特性也有顯著的延遲。樣品H0首先在6分鐘時滴加，然後分別為樣品MIC（10.75分鐘）、H1（11.7分鐘）、H2（13.32分鐘）和H3（19.57分鐘）。在前測中，冰淇淋的整體接受度使用9分制喜好程度量表來評估，1表示”非常不喜歡”、5 表示”無感”和9表示”非常喜歡”。其中，得分為8.6分的配方H2最受歡迎，與得分為8.5的H3和MIC無差異。樣本H1得分為7.3分，而H0得分最低為4.7分。感官分析的接受度隨著酪梨油在冰淇淋中的乳固體非脂肪（脫脂奶粉）含量增加而增加。描述性分析中，未包括在前測裡最不受歡迎的樣品H0。對於屬性強度使用描述性的9分制喜好程度量表，其中1表示”最小強度”、5表示“不小也不大”和9表示”最大強度”。因為脫脂奶粉的增加使顏色變為乳白色，H2、H3與MIC相較之下在外觀上沒有差異。 Msnf增加了甜度、乳白、熟牛奶、乳脂和香草的口味強度。 H2的氣味與MIC沒有差別。質地屬性顯示出厚度、光滑度，脂肪感和口腔醇度增加，隨著Msnf增加，結冰性降低。餘味屬性（甜度、乳白、熟牛奶、乳脂和香草味）也隨著Msnf和MIC的增加而增加，與H2和H3沒有差異。對於整體樣品喜好前測，使用9分制喜好程度量表，MIC (7.30分) 、H1(5.73分) 、H2(7.02分) 和H3(6.38) 。儘管MIC（乳脂）的總得分為最高7.30分，但與H2（7.02分）沒有太大差異。與乳脂製作的冰淇淋相比， 25%Msnf酪梨油含量的冰淇淋顯著的被接受。

關鍵詞：冰淇淋，酪梨油，感官評價

關鍵字

冰淇淋 ； 酪梨油 ； 感官評價

並列摘要

Ice cream is a favourite frozen dessert around the world and it has a high content of saturated fat and cholesterol which may result in lifestyle related diseases. The substitution of milk fat with unsaturated fatty acids has been proven to reduce the risk of cardio vascular diseases. Avocado oil is oil that has substantial amount of unsaturated fatty acid. The abundance of avocados in the Kingdom of Eswatini would make this a viable choice. Expansion of avocado oil into the frozen dessert industry is another way of reducing the consumption of saturated fats. The main objective of this study was to develop ice creams with avocado oil replacing milk fat with varying amounts of skim milk powder (Msnf). Ice cream formulations of 15 % fat content were prepared based on the use of milk fat in comparison to avocado oil. Sample MIC (milk fat based ice cream), and avocado oil based ice creams H0 (10 % Msnf), H1 (20 % Msnf), H2 (25 % Msnf) and H3 (40 % Msnf) were investigated through their physicochemical properties, sensory attributes and consumer acceptability. The physicochemical properties of ice cream analysed included pH, titratable acidity, melting characteristics and moisture content. Pre-test sensory evaluation was done whereby 10 participants used the 9 hedonic scale based on appearance, taste, flavour, texture and overall acceptability. A follow up descriptive test was done based on the results of preliminary test by 42 participants on the sensory attributes using descriptive 9-point scale for each attribute. Results of the study showed MIC had pH 6.52 and titratable acidity 0.17 %. Avocado oil based ice cream had pH range 6.46-6.49 and titratable acidity range of 0.175-0.21 %. Avocado oil based ice cream samples showed a decrease in pH with increasing skim milk powder. Melting characteristics show significant delayed first drop in avocado oil samples as skim milk powder is increased. Sample H0 was first to drip at 6 minutes followed by sample MIC (10.75 min), H1 (11.7 min), H2 (13.32 min) and H3 (19.57 min), respectively. In pre-test overall acceptability of ice cream was assessed using a 9-point hedonic scale, 1 represented ‘dislike extremely’, 5 - ‘neither dislike nor like’ and 9 - ‘like extremely’. Formulation H2 was mostly liked with a score of 8.6 which was not different from H3 and MIC both with a score of 8.5, sample H1 had a score of 7.3 and H0 was least liked with a score of 4.7. Acceptability scores of sensory attributes increased with increase of milk solids non-fat (skim milk powder) in avocado oil based ice cream. For the descriptive analysis, sample H0 was not included as it was least liked in the pre-test. A descriptive 9 - point scale was used for attribute intensities whereby 1 represented the least intensity, 5- for ‘neither least nor more’ and 9 – strong intensities. For appearance, H2 and H3 were not different from MIC as an increase of skim milk powder intensified the colour to cream white. Flavour intensities of sweetness, milky, cooked milk, creaminess and vanilla tastes increased with Msnf. Flavour for H2 was not different from MIC. Texture attribute shows increased thickness, smoothness, fat feel and mouth coating, with decrease in iciness as Msnf is increased. Aftertaste attributes (sweet, milky, cooked milk, creamy and vanilla) also increases with increased Msnf and MIC not different from H2 and H3. For overall sample liking, the 9-point hedonic scale was used as in pre-test. MIC, H1, H2 and H3 had an overall score 7.30, 5.73, 7.02 and 6.38 respectively. Although MIC (milk fat based) had the highest overall score of 7.30, it was not different from H2 (7.02). Avocado oil based ice cream with 25 % Msnf is significantly accepted in comparison the milk fat based ice cream by score.
Keywords: ice cream, avocado oil, sensory evaluation

並列關鍵字

ice cream ； avocado oil ； sensory evaluation

參考文獻

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