羽衣甘藍(lán)怎么吃更營(yíng)養(yǎng)

Kale has grown in popularity over the past decade and has become somewhat of a cultural icon, complete with celebrity endorsements, social media hashtags, and even kale merchandise. Think back to the social media craze of the "KALE" Ivy League-inspired sweatshirt. Fashion aside, the kale trend taught us there are so many ways to love this nutrient-dense green, including blending, sautéing, massaging, and air-frying. But are some preparation methods better than others when it comes to optimizing nutritional content and absorption? Science suggests they are. But before diving into the science, let's highlight that kale's a member of the brassica species, similar to Brussels sprouts, broccoli, and cauliflower. Kale's considered a superfood by health experts due to its abundance of vitamins A, B6, C, K, calcium, copper, potassium, and manganese (via Mayo Clinic Health System). When scientists study the impacts of cooking kale and other brassica plants, they're typically considering nutrient and mineral breakdown and bioavailability (our body's ability to absorb those nutrients and minerals).

過(guò)去的十年，羽衣甘藍(lán)越來(lái)越受歡迎，并已成為某種文化象征，擁有名人代言、社交媒體標(biāo)簽，甚至羽衣甘藍(lán)商品。回想一下社交媒體對(duì)“羽衣甘藍(lán)”常春藤聯(lián)盟運(yùn)動(dòng)衫的狂熱。撇開(kāi)時(shí)尚不談，羽衣甘藍(lán)的流行趨勢(shì)告訴我們有很多方法可以愛(ài)上這種營(yíng)養(yǎng)豐富的綠色蔬菜，包括拌、炒、腌和煎炸。但是，在優(yōu)化營(yíng)養(yǎng)成分和吸收方面，有些制作方法是否比其他方法更好呢?科學(xué)表明是的。但在深入研究這門科學(xué)之前，讓我們先強(qiáng)調(diào)一下羽衣甘藍(lán)是蕓苔屬植物的一種，類似于芽甘藍(lán)、西蘭花和菜花。羽衣甘藍(lán)被健康專家視為超級(jí)食品，因?yàn)樗缓S生素a、B6、C、K、鈣、銅、鉀和錳(通過(guò)梅奧診所健康系統(tǒng))。當(dāng)科學(xué)家研究烹飪甘藍(lán)和其他蕓苔屬植物的影響時(shí)，他們通常會(huì)考慮營(yíng)養(yǎng)和礦物質(zhì)的分解以及生物利用度(我們身體吸收這些營(yíng)養(yǎng)和礦物質(zhì)的能力)。

A 2018 study in the International Journal of Food Sciences and Nutrition studied the effects of steaming, boiling, microwaving, pressure-cooking, and vacuum-cooking (sous-vide) kale. They concluded that all the cooking methods yielded a loss of antioxidants, flavonoids, minerals, and organic acids, compared to fresh kale, with the biggest adverse effect on calcium. Steaming was deemed the best way to preserve antioxidants and bioactive compounds. However, a 2019 study found that sous-vide may be the best method to cook and preserve kale's nutrients, particularly because of its ability to preserve vitamin C more effectively, according to the Journal of the Science of Food and Agriculture. P-coumaric and gallic acids, two important phytochemicals in kale, remained most stable when cooked via sous-vide. Both methods are considered gentler forms of cooking, and sous-vide in particular is a cooking method performed at low temperatures, suggesting the amount of heat and the amount of time the vegetable is exposed to heat can impact nutritional quality.

《國(guó)際食品科學(xué)與營(yíng)養(yǎng)學(xué)雜志》2018年的一項(xiàng)研究研究了蒸煮、煮沸、微波、壓力蒸煮和真空蒸煮(sous vide)甘藍(lán)的影響。他們得出結(jié)論，與新鮮羽衣甘藍(lán)相比，所有烹飪方法都會(huì)產(chǎn)生抗氧化劑、類黃酮、礦物質(zhì)和有機(jī)酸的損失，對(duì)鈣的負(fù)面影響最大。其中，蒸煮被認(rèn)為是保存抗氧化劑和生物活性化合物的最佳方法。然而，據(jù)《食品與農(nóng)業(yè)科學(xué)雜志》報(bào)道，2019年的一項(xiàng)研究發(fā)現(xiàn)，真空蒸餾法可能是烹飪和保存羽衣甘藍(lán)營(yíng)養(yǎng)成分的最佳方法，特別是因?yàn)樗芨行У乇４婢S生素c。對(duì)香豆酸和沒(méi)食子酸是羽衣甘藍(lán)中兩種重要的植物化學(xué)物質(zhì)，經(jīng)真空蒸煮后保持最穩(wěn)定。這兩種方法都被認(rèn)為是比較溫和的烹飪方法，特別是真空蒸餾法是一種在低溫下進(jìn)行的烹飪方法，這表明加熱量和加熱時(shí)間的長(zhǎng)短會(huì)影響蔬菜的營(yíng)養(yǎng)品質(zhì)。

Raw kale may be harder to digest than cooked due to its fiber content, and if dietary fiber intake is increased too drastically, it can often cause digestive upset, according to SF Gate. If digestive upset occurs when eating raw kale, you may want to opt for a gentle steam, making the leaves softer and easier to digest. However, if you prefer to eat kale raw, consider cutting out the stem. The stem can be very tough and fibrous, making it even more difficult to digest than the leaves alone. Another healthy way to enjoy raw kale is to massage it. This is often done by chopping kale, adding it to a large bowl, drizzling vinegar or citrus over the top and squeezing the leaves with your hands and fingers. Acids and vinegar help break down the cellulose, thereby reducing its toughness, according to Bon Appetit. Since kale is such a fibrous vegetable, you can massage and then store it in the refrigerator for several days before it becomes unpalatable.

根據(jù)SF Gate的說(shuō)法，生羽衣甘藍(lán)由于其纖維含量豐富，可能比熟羽衣甘藍(lán)更難消化，因?yàn)樯攀忱w維攝入過(guò)多，會(huì)導(dǎo)致消化不良。如果在吃生羽衣甘藍(lán)時(shí)出現(xiàn)消化障礙，你可以選擇溫和的蒸煮一下，這樣葉子會(huì)更柔軟，更容易消化。然而，如果你喜歡生吃羽衣甘藍(lán)，可以考慮去掉它的莖。因?yàn)榍o較硬，纖維狀，比葉子更難消化。另一種享受生羽衣甘藍(lán)的健康方式是腌。通常是通過(guò)切碎羽衣甘藍(lán)，將其加入一個(gè)大碗中，在上面撒上醋或柑橘，然后用手和手指擠壓葉子來(lái)完成的。根據(jù)Bon Appetit的說(shuō)法，酸和醋有助于分解纖維素，從而降低其韌性。由于羽衣甘藍(lán)是一種纖維狀蔬菜，腌后可以在冰箱里儲(chǔ)存幾天。