皮克林乳液結合水膠製備凍融穩定性脂肪模擬物

Abstract

植物肉是近期食品產業中的重要趨勢之一，如今以植物模擬肉品蛋白質的技術已十分成熟，然而油脂部分的模擬則尚在發展中，動物脂肪因為是油脂儲存於細胞中的構造，與植物油脂之性質相當不同，現今的植物肉如漢堡排等產品往往使用飽和脂肪酸含量較高之植物油脂，如棕櫚油、可可油或椰子油等，模擬真實肥肉脂肪在漢堡排表面的白色顆粒或紋路感。然而，植物油脂與動物脂肪不同，其在經過加熱後，會直接融化成液態進而流失，可能造成產品外觀在烹調後形成視覺不佳的孔洞，甚或影響質地及適口性。因此，有必要針對植物肉之脂肪部分進行相關的模擬及測試，以解決此一問題。本研究採皮克林乳化技術為研究平台，並搭配水膠以模擬漢堡排中肥肉脂肪結構與口感，期許其能因良好的抓水能力提供足夠之凍融穩定性，以應用於冷凍食品中，並測試經此方式製作出的樣品之各項物化性質，以確定其質地特性及安定性。 乳化穩定性的結果顯示，在油水比(φ) 0.6、均質時間5 min、轉速12,000 rpm，以及穩定劑-大豆蛋白(soy protein isolate, SPI)濃度為3%，並添加40 mM NaCl的條件下，製備的乳液穩定性最佳。然而，經過測試發現此乳液凍融穩定性不佳，因此嘗試了將大豆蛋白醣基化(gSPI)作為穩定劑使用，然測試其凍融性亦無法達標。基此，轉於卡德蘭膠之製膠製程中，摻混介質研磨纖維素(media-milled cellulose, MC)，期待能使脂肪模擬物凍融穩定性的提升。結果顯示，SPI組別脂肪模擬物其整體凍融穩定性效果會較gSPI組別佳，而在SPI組別中，卡德蘭膠搭配5% 5 min MC組、3% 60 min MC組及5% 60 min MC組在三次凍融循環下相較他組能表現較佳凍融穩定性，其在三次循環後可維持穩定性在89%以上。 經流變試驗及油煎試驗可見脂肪模擬物的熱穩定性良好，因此推測，將脂肪模擬物添加到漢堡排中，可以成功模擬動物肥肉的外觀，呈現出白色顆粒狀，並且不會隨烹煮溫度升高而流失造成孔洞。而油煎測試結果顯示3% 60 min MC添加組別的油、水釋放的情況更好，顯示此組樣品可能相對可以提供較佳的多汁性及濕潤性口感。

Plant-based meat is one of the prominent trends in the food industry in recent years. The technology for producing plant-based protein that mimics meat has become highly advanced. However, the simulation of fats is still under development. Animal fats, being stored in cells, have different properties compared to plant fats. Current plant-based meats, such as burgers, often use plant oils with a higher saturated fatty acid content, such as palm oil, cocoa butter, or coconut oil, to simulate the white specks or marbling of real fatty meat on the surface of the burger patty. However, plant fats behave differently from animal fats. When heated, plant fats tend to melt into a liquid and may cause undesirable cavities in the product's appearance. Therefore, it is necessary to conduct relevant simulations and tests specifically for the plant-based fat component to address this issue. This study adopted the Pickering emulsion technique as a research platform and combines hydrogels to simulate the structure and texture of fatty meat in burger patties. With their good water-holding capacity, it was expected that the hydrogels will provide sufficient freeze-thaw stability for application in frozen foods. The physicochemical properties of the samples produced by this method were tested to determine their texture characteristics and stability. The results showed that the best stability of the emulsion is achieved at an oil-water ratio (φ) of 0.6, a homogenization time of 5 minutes with rotational speed of 12,000 rpm, stabilizer concentration of 3%, and the addition of 40 mM NaCl. However, it was found that the emulsion did not exhibit freeze-thaw stability. Therefore, glycated soy protein isolate (gSPI) was attempted as a stabilizer but failed to meet the freeze-thaw stability requirements. In further processing, media-milled cellulose (MC) was added during the processing of gel preparation with curdlan, aiming to improve the freeze-thaw stability of the oil-gel system. The results showed that the overall freeze-thaw stability of the SPI (soy protein isolate) group was better than that of the gSPI (glycated soy protein isolate) group. Within the SPI group, the curdlan combined with 5% 5-min-MC, 3% 60-min-MC, and 5% 60-min-MC exhibited better freeze-thaw stability after three cycles, maintaining the freeze-thaw stability above 89%. Rheological and pan-frying tests showed that the fat analogue had good thermal stability. Therefore, it is speculated that by adding the fat analogue to burger patties, it can successfully simulate the appearance of animal fat, presenting a white speckled appearance without losing integrity or creating holes as the cooking temperature rises. The pan-frying test results showed that the group with 3% 60-min-MC addition had better release of oil and water, indicating that this sample group may provide better juiciness and moistness in terms of texture.