Kamis, 11 Februari 2010

Segala Tentang Telur


Telur

Sumber protein hewani selain daging, ikan, susu

Telur yang dikonsumsi:

  • Telur unggas: telur ayam, telur bebek, telur puyuh, telur angsa
  • Telur ikan
  • Telur penyu

Penggunaan Telur?

  • Dicampurkan dalam adonan untuk pembuatan: roti, cake, es krim, mayones, saus, puding, dll
  • Dihidangkan sebagai snack (telur rebus): telur rebus yang masih bercangkang, 
    telur rebus yang sudah dikupas -> diolah lebih lanjut: rendang telur, telur coklat, dll
  • Diolah menjadi telur asin

Telur Rebus

Cangkang utuh

Albumen tidak menempel pada cangkang

Kriteria telur rebus:

  • Cangkang tidak pecah selama perebusan
  • Cangkang mudah dikupas dan albumen tidak melekat pada cangkang
  • Kuning telur terletak di bagian tengah  

Faktor-faktor yang Mempengaruhi Pecahnya Cangkang Selama Perebusan:

  • Ketebalan cangkang
  • Ukuran dan bentuk cangkang
  • Umur telur
  • Suhu penyimpanan
  • Suhu awal dari air yang digunakan untuk merebus

Kemudahan Proses Mengupas Telur

Dipengaruhi 2 faktor pengupasan:

  • Waktu yang dibutuhkan untuk menghilangkan cangkang
  • Kenampakan telur rebus setelah dikupas

pH putih telur > 8.7 lebih mudah dikupas

Penyimpan dingin menghambat peningkatan pH  sehingga telur sulit dikupas

Pendinginan cepat setelah perebusan dan pemanasan kembali dalam waktu singkat  dapat meningkatkan kemudahan kupas

Kuning telur

Telur berkualitas tinggi -> kuning telur terpusat 

Kualitas kuning telur dipengaruhi beberapa faktor:

  • Posisi penyimpanan
  • Posisi perebusan
  • Umur telur

Perubahan Warna Kuning Telur:

Fe dari kuning telur bereaksi dengan H2S dari putih telur menjadi FeS yang berwarna kehijauan

Metode Perebusan (American Egg Board)

Telur 1 lapis dalam panci yang telah ditambah air paling sedikit 1 inci di atas telur

Ditutup dan dipanaskan sampai mendidih, sumber panas dimatikan dan dibiarkan sampai 15 – 17 menit. Segera dinginkan dengan air dingin untuk mencegah permukaan kuning telur berwarna gelap  

Metode Mengupas Telur (American Egg Board)

  • Dinginkan telur rebus secara cepat dengan air mengalir (5 menit)
  • Retakkan cangkang pada seluruh permukaan dengan membenturkan perlahan pada meja
  • Putar telur di antara tangan untuk melonggarkan cangkang
  • Kupas mulai pada ujung tumpul 

What is Egg???


Air cell - an empty space located at the large end of the egg; it is between the inner and outer shell membranes.

Chalaza - a spiral, rope-like strand that anchors the yolk in the thick egg white. There are two chalazae anchoring each yolk, one on the top and one on the bottom. (The plural of chalaza is chalazae.)

Germinal disc or blastodisc - a small, circular, white spot (2-3 mm across) on the surface of the yolk; it is where the sperm enters the egg. The nucleus of the egg is in the blastodisc.

Inner shell membrane - the thin membrane located between the outer shell membrane and the albumin.

Outer shell membrane - the thin membrane located just inside the shell.

Shell - the hard, protective coating of the egg. It is semi-permeable; it lets gas exchange occur, but keeps other substances from entering the egg. The shell is made of calcium carbonate.

Thick albumin - the stringy part of the egg white (albumin) located nearest the yolk.

Thin albumin - the watery part of the egg white (albumin) located farthest from the yolk.

Vitelline (yolk) membrane - the membrane that surrounds the yolk.

Yolk - the yellow, inner part of the egg where the embryo will form. The yolk contains the food that will nourish the embryo as it grows.  

Egg Quality???

Grade AA: A 'Grade AA' egg will stand up tall. The yolk is firm and the area covered by the white is small. There is a large proportion of thick white to thin white

Grade A: A 'Grade A' egg covers a relatively small area. The yolk is round and upstanding. The thick white is large in proportion to the thin white and stands fairly well around the yolk.

Grade B: A 'Grade B' egg spreads out more. The yolk is flattened and there is about as much (or more) thin white as thick white.

Some Important Egg Tips 

  • Use only properly refrigerated, clean, sound shelled, fresh, grade AA or A eggs.
  • Buy eggs from refrigerated cases. Always refrigerate eggs at home.
  • Store eggs in the carton on a shelf in the refrigerator to ensure freshness.
  • Egg shell and yolk color may vary, but color has nothing to do with egg quality, flavor,nutritive value, cooking characteristics or shell thickness.
  • Poach eggs instead of frying to cut back on fat, or use non-stick pans or non-stick vegetable pan spray to reduce fat when preparing eggs.
  • Prepare and serve eggs with low-fat foods such as vegetables, fruits, whole grain breads, and low fat or skim-milk cheeses.
  • Serve egg dishes promptly or keep them refrigerated.