PROTEIN Dr. Annis Catur Adi Dept Gizi Kesehatan Fakultas Kesehatan Masyarakat Universitas Airlangga

Complete proteins Incomplete proteins Legumes Protein ditemukan didlm setial sel. Protein berasal (bahasa Yunani): “Primary, holding first place” yg berarti menduduki tempat yang terutama. Protein adalah penting bagian sel-sel Protein disusun dari unsur carbon, hydrogen, oxygen, and nitrogen , yg dibentuk kedalam “basic unit” dinamakan amino acids. Terdapat 20 AA. 8-10 macam essensial, harus dibentuk dari luar tubuh (bentuk jadi dari makanan sehari-hari) Complete proteins Incomplete proteins Legumes

Ada 8 AA esensial untuk org dewasa (Isoleusin, Leusin, Lisin, Metionin, Fenilalanin, Treonin, Triptofan dan Valin), dan 10 AA esensial pada anak-anak ( 8 AA + arginin dan histidin) Jenis protein menurut AA: Complete protein :protein yg mengandung AA esensial lengkap (jumlah & jenisnya). Berasal sumber hewani. Contoh: Kasein pd susu, Albumin pd putih telur Incomplete/Partiallly complete protein : protein yg tdk mengandung AA esensial atau sedikit. Berasal sumber nabati. Contoh Zein pada jagung dan protein nabati lainnya. Partiallly complete protein : protein yg mengandung AA esensial lengkap, tetapi beberapa diantaranya hanya sedikit. Contoh Legumin pada kacangan-kacangan, Gliadin pd gandum,dll

Fungsi of Protein Pertumbuhan dan pemeliharaan Jar. Tubuh Protein sbg bhn pembangun jar. baru. Sbg zat pembangun: bagian inti sel, bagian padat jaringan dlm tubuh (otot, sel-2/butir darah), bagian enzim, hormon, antibodi, dll. Protein sebagai pengatur: kelangsungan proses-proses di dlm tubuh. Hormon, enzim, tekanan osmosis, keseimbangan pH Protein sebagai bahan bakar: mengandung karbon. Mensuplai 4 Kal/gram, scr ekonomi sumber energi yg mahal drpd KH dan Lemak. Kecukupan: 10-15% tot Kal. = 210 Kal = 52,5 g

Sumber protein Protein dgn nilai biological tinggi, terutama pd pangan hewani: daging, ikan, telur, keju dan susu.. Protein dgn nilai Biological rendah, terutama berasal dari: pangan nabati: kacang-kacangan, polong, sereal, dll

Metabolisme 15% - 20% diet seharusnya dari protein Pencernaan protein: pecah menjadi asam amino (dilambung), diserap dinding usus halus. ( 60% diserap usus halus atas, 28 % di usus besar dan 12 % telah mulai dilambung). Faktor yg pengaruhi kebutuhan protein : 1) BB, 2) Umur dan jenis kelamin (anak kecil 4x dewasa), 3) Mutu protein (nilai cerna dan serap), dan 4) Pertumbuhan

Nitrogen balance and protein requirements Introduction to Nutrition and Metabolism, 4th edition, CRC Press, Boca Raton. Presentation © copyright David A Bender 2007

Nitrogen balance and protein requirements In children who are growing, the need for dietary protein is obvious Why does an adult, who is not growing require a dietary intake of protein ? Introduction to Nutrition and Metabolism, 4th edition, CRC Press, Boca Raton. Presentation © copyright David A Bender 2007

An overview of protein metabolism dietary protein 80 g enzymes intestinal cells mucus 70 g body protein ~ 10 kg amino acids dipeptides amino acids metabolites urine excretion (70 g) fecal loss (10 g) Introduction to Nutrition and Metabolism, 4th edition, CRC Press, Boca Raton. Presentation © copyright David A Bender 2007

Urinary N metabolites urea 10 – 35 g /day ammonium ions 340 – 1200 mg /day amino acids 1.3 – 3.2 g /day uric acid 250 – 750 mg /day creatinine women 1.2, men 1.8 g /day creatine < 50 mg /day Introduction to Nutrition and Metabolism, 4th edition, CRC Press, Boca Raton. Presentation © copyright David A Bender 2007

Nitrogen balance = intake - excretion fecal loss (10 g) urine excretion (70 g) amino acids dipeptides metabolites body protein ~ 10 kg dietary protein 80 g enzymes intestinal cells mucus 70 g Introduction to Nutrition and Metabolism, 4th edition, CRC Press, Boca Raton. Presentation © copyright David A Bender 2007

Nitrogen balance = intake - excretion N balance or equilibrium normal state in an adult no change in body protein content fecal loss (10 g) urine excretion (70 g) amino acids dipeptides metabolites body protein ~ 10 kg dietary protein 80 g enzymes intestinal cells mucus 70 g Introduction to Nutrition and Metabolism, 4th edition, CRC Press, Boca Raton. Presentation © copyright David A Bender 2007

Nitrogen balance = intake - excretion positive N balance or equilibrium increase in body protein content normal in growth, pregnancy and recovery from loss fecal loss (10 g) urine excretion (70 g) amino acids dipeptides metabolites body protein ~ 10 kg dietary protein 80 g enzymes intestinal cells mucus 70 g Introduction to Nutrition and Metabolism, 4th edition, CRC Press, Boca Raton. Presentation © copyright David A Bender 2007

Nitrogen balance = intake - excretion negative N balance decrease in body protein content never normal; indicates illness, trauma or inadequate intake fecal loss (10 g) urine excretion (70 g) amino acids dipeptides metabolites body protein ~ 10 kg dietary protein 80 g enzymes intestinal cells mucus 70 g Introduction to Nutrition and Metabolism, 4th edition, CRC Press, Boca Raton. Presentation © copyright David A Bender 2007

Several studies show the average requirement = 0.66 g /kg body weight N balance: determination of protein requirements Several studies show the average requirement = 0.66 g /kg body weight Safe and adequate level of intake = 0.825 g /kg body weight (UK average = 1.2) Safe and adequate level of intake = 8% of energy intake (UK average = 15) Introduction to Nutrition and Metabolism, 4th edition, CRC Press, Boca Raton. Presentation © copyright David A Bender 2007

Protein deficiency is unlikely in an adult Safe and adequate protein intake is 8.25 % of energy intake If you can eat enough of most “starchy” staples to meet energy needs you will meet your protein requirements Introduction to Nutrition and Metabolism, 4th edition, CRC Press, Boca Raton. Presentation © copyright David A Bender 2007

Protein turnover in the fed and fasting states mmol /hour synthesis catabolism fed 8.8 8.1 fasting 6.4 7.85 In the fasting state amino acids from protein breakdown are being used for gluconeogenesis and as metabolic fuel In the fed state there is an ample energy supply to permit protein synthesis Introduction to Nutrition and Metabolism, 4th edition, CRC Press, Boca Raton. Presentation © copyright David A Bender 2007

Percentage of energy expenditure at rest Introduction to Nutrition and Metabolism, 4th edition, CRC Press, Boca Raton. Presentation © copyright David A Bender 2007

The fed state – ample fuels entering from the gut glycogen triacyglycerol protein glucose triacylglycerol in chylomicrons triacylglycerol in VLDL amino acids glucose glycogen protein amino acids Introduction to Nutrition and Metabolism, 4th edition, CRC Press, Boca Raton. Presentation © copyright David A Bender 2007

The fasting state – utilization of body reserves amino acids glucose triacyglycerol hormone-sensitive lipase protein glucose ketone bodies amino acids glycerol fatty acids fatty acids glycogen Introduction to Nutrition and Metabolism, 4th edition, CRC Press, Boca Raton. Presentation © copyright David A Bender 2007

Ringkasan Protein Protein : zat pembangun tubuh. Pembentukan jaringan dan memelihara kesehatan tubuh. Sumber protein: hewani dan nabati Mutu protein hewani lbh tinggi dari nabati Mutu protein dpt ditingkatkan dengan: * mengkonsumsi berbagai protein * menambah ikan, telur,daging meski hanya sedikit

Ringkasan Protein (keseimbangan N)

Annis CA/ Dept Gizi Kesmas/ FKM-UA Sekian & Terimakasih Annis CA/ Dept Gizi Kesmas/ FKM-UA