Bagaimana Nasi Kerabu Mendapat Warna Biru?

Nasi kerabu merupakan hidangan popular yang berasal dari negeri Kelantan. Pada kebiasaannya ia dihidangkan bersama sambal tumis, kerisik (sambal) ikan, ulam-ulaman, lada solok, telur asin, ikan celup tepung, daging bakar dan ayam percik. Oh! Jangan lupa keropok, budu dan air sirap ais! Lazatkan? 

Saya terpanggil untuk menghasilkan sebuah dokumentasi perkongsian ringkas mengenai warna biru pada nasi kerabu seusai sambutan iftar keluarga baru-baru ini. Anak sayalah yang bertanyakan soalan cepu emas ini. Jom kita kupas jawapannya satu persatu. 

Pertama sekali, ingin saya memperkenalkan sejenis bunga yang bertanggungjawab ke atas persoalan ini. Bunga nasi kerabu berwarna biru nila (indigo), yang dikenali juga sebagai bunga Telang berasal dari spesis pokok kekacang yang hidup memanjat. Bunganya menjadi pewarna makanan popular sejak zaman dahulu lagi.

Ringkasan taksonomi bunga Telang

Jadi, bagaimana caranya untuk menghasilkan pewarna nasi kerabu? Saya memetik beberapa kuntum bunga Telang dari halaman ibu untuk tujuan perkongsian ini. Bunga tersebut direndam dalam secawan air suam (tidak terlalu panas supaya ia tidak kehilangan khasiatnya). Air biru nila yang terhasil di gunakan untuk memasak nasi kerabu. Sudah pasti bahan lain sebagai pembangkit aroma nasi seperti serai, daun lima purut dan daun pandan ditambah bersama beras tadi. Masak nasi seperti biasa dan anda akan dapati warna nasi anda berwarna biru!

Anthocyanin (Antosianin) adalah sebatian kimia semulajadi yang memberi pigmen biru pada bunga Telang. Antosianin juga boleh didapati pada buah-buahan seperti beri dan buah senduduk, bunga seri pagi dan sayur-sayuran seperti kobis merah (red cabbage) dan terung. Sebatian kimia ini tidak berbahaya malah dipercayai boleh menjadi agen awet muda! Selain daripada digunakan sebagai pewarna makanan untuk nasi kerabu dan kuih-muih, ia juga digunakan dengan meluas sebagai nila atau pewarna fabrik semulajadi. 

Mahu cuba ekperimen lain menggunakan pewarna anthocyanin ini? Ini petunjuknya… Anthocyanin sebenarnya penunjuk pH semulajadi. Ia boleh digunakan untuk menguji keasidan atau kealkalian sesuatu larutan. Sebagai contoh, jika anda menitiskan sedikit air sabun, larutan biru “berantosianin” (dari rendaman bunga Telang) akan bertukar daripada warna biru kepada warna biru kehijauan. Apa lagi? Cubalah uji larutan atau cecair yang anda boleh perolehi di sekitar dan dalam rumah seperti pencuci lantai, syampu, cuka dan air paip. Lihat perubahan warna pada ditunjukkan oleh larutan ajaib (rendaman bunga Telang) itu dan beritahu kami!

Shared by Izhana
Guest Blogger

Plant-based hues for dyes!



After living for umpteen years, I have never thought of identifying what is it that creates the vibrant colors that I see and adore every day. Generally, I thought that colours for dyes are only made from mixtures of three primary colors which are cyan, magenta and yellow.  But little did I know until my mother told me, that plants which include the tree, leaves, flowers and roots have hues that function as a source in making dyes including food colouring. The first thing that came to mind was the thought of mans cruelty to use such beauty as a colouring source.

Hey pretty!

But after sourcing for some information, it seemed that plants have been used to make dyes for decades. Here are some examples:

  

Let’s start with the famously known Henna tree which is also known as Pokok Inai in Malay. Henna is a very unique plant where all you have to do is just pound the leaves and you can obtain its intense natural reddish-orange hue. Because of that, Henna has been widely used as a dye for hair, skin and fingernails. You would have probably seen hair dyes in black and brown, but that isn’t the original color of the Henna plant. The natural and original Henna plant only produces reddish-orange hues. 

Scientific name: Lawsonia inermis (Henna)

Other than Henna, turmeric or kunyit in Malay, which is known as a cooking spice also acts as food dye, as the turmeric rhizome has a limitless natural yellow pigment ranging from bright yellow to deep orange, depending on the variety. It can just turn everything yellow! Some Malaysian dishes that use turmeric are chicken turmeric, yellow glutinous rice and gulai lemak.



Scientific name: Curcuma longo (Turmeric)

The third example is the Butterfly Pea plant, also known as Bunga Telang. This plant also contributes a purplish-blue hue for food dye. Try to guess which Malaysian food uses this plant as food dye. It’s Nasi Kerabu! I was actually so excited when I heard that Nasi Kerabu got its colour from a plant because I literally love to see the colour of the Nasi Kerabu and it is also one of my favourite dishes.

Scientific name: Clitoria flower (Butterfly Pea Plant)

It’s amazing how plants can be a source for dyes. In fact, there are many other plants which could also be used for food colouring. Some other examples are roselles, blueberries, pandan leaves and red dragon fruits. Taking natural plant-based food colouring is much healthier than consuming artificial colouring even though the bright colours may be appealing to your eyes. Plant-based hues also produce softer and more natural tones compared to artificial colouring. So, perhaps next time you can use plant-based hues to add colour to your homemade food; but keep in mind that not all plants can be used as food dye! Get recommendations from people or source for information on the internet to ensure that it is edible.

Shared by Ruby, Intern at Petrosains