KARAKTERISTIK KOMODITAS HASIL PERTANIAN:
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Tujuan Matakuliah: Mahasiswa mengetahui dan memahami karakteristik bahan hasil pertanian dan mengetahui efek pengolahan terhadap karakteristiknya.
Komoditas Hortikultura • Karakteristik buah dan sayur • Perubahan karakteristik akibat proses pananganaan dan pengolahan
Komoditas ubi-ubian • Karakteriistik umum ubi-ubian • Perubahan karakteristik akibat proses
Komoditas serealia dan kacang-kacangan • Karakteristik umum serealia dan kacang-kacangan • Perubahan karakteristik akibat proses
Komoditas rempah-rempah - Karakteristik umum rempah-rempah - Perubahan karakteristik akibat proses
Horticultural Commodity Fruit
◦ Climacteric ◦ Non climacteric Vegetable
◦ Non climacteric Flower
◦ Non climacteric
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Klimaterik = suatu periode auto stimulation terjadi serangkaian perubahan biologis yg diawali dengan terjadinya peningkatan respirasi dan proses pembentukan etilen secara autokatalitis sehingga beralihnya fase pertumbuhan menjadi tua dan buah menjadi matang setelah panen periode klimaterik ini tetap berlangsung Gol. Buah klimaterik : pepaya, mangga, pisang, tomat dll. Non-Klimaterik = respirasi cenderung turun tdk terjadi peningkatan respirasi Gol. Non-klimaterik : jeruk, srawberry, timun, blewah, melon, semangka
Pola Respirasi buah selama Fase Pengembangan Rate (Jml CO2) fruit growth
respiration climacteric respiration nonclimacteric pertumbuhan
maturation ripening senescence
Tanaman Sebagai bhn pangan Akar
Batang
Daun
Bunga
Buah
Biji
Sayur dan Buah
Sayur dan buah secara anatomi tdk dpt dibedakan Dibedakan berdasarkan penggunaannya : - Sayur biasa dimakan bersama makanan utama (nasi) -Buah sebagai dessert ( dimakan segar )
BUAH = bagian tanaman hasil perkawinan putik dan benangsari mrpk tempat biji mempunyai rasa manis asam, warna dan aroma yang khas
SAYURAN = bagian tanaman (akar, daun, buah, biji, batang ) umumnya tanaman yang umurnya relatif pendek tdk berasa manis, warna dan tekstur yang beragam
tomat, terong , timun, cabe secara anatomi adalah buah tetapi digolongkan sebagai sayuran
Buah dan sayur sangat beragam tergantung dari tempat tumbuh dan iklim
Setelah dipanen buah dan sayur akan menjadi rusak bila tidak dilakukan penanganan yang tepat
Penanganan pasca panen dapat :
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mengurangi tk kerusakan (daya simpan meningkat)
-
meningkatkan kualitas hasil panen
Chemical Composition
Water
More than 70 % Affect perishability of commodity Affect physical characteristics of product Decreasing of moisture content leading to softening of plant tissue, wrinkle and lack of shape
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Carbohydrates Represent more than 90 % of dry matter Sugar such as glucose, fructose, maltose and sucrose, all share the following characteristics : - supply energy for nutrition - readily fermented by …… - may used as a preservative - on heating they darken colour .. - combine with … to give dark colour as … 11
Starches
- supply energy in nutrition - firming of plant tissues Pectin and carbohydrates gums - in colloidal solution contribute to viscosity - in solution with sugar and acid are the basis of jelly Cellulose and hemicellulose - act primarily as supporting structures - insoluble in cold and hot water - not digested, not yield energy 12
Mineral Substances 0,6
– 1,80 % ( K, Na, Ca, Mg, Fe, Mn, Al, P, Cl,
S) salt of organic acid complex organic combination (chlorophyll, lecithin, etc) Ca and P essential for calcium fixation (Ca/P) : 0,7 for adults and 1,0 for children vegetable rich in P and Ca : green bean, cabbage and onion fruit rich in P and Ca : pears, lemon, oranges 13
Vitamins function as enzyme systems which facilitate the metabolism Divided into two major groups (fat soluble and wet soluble) Examples : Vitamin A/ Retinol found in the orange and yellow vegetables and green leafy vegetables Vit C / ascorbic acid and Vit E favours the absorption of iron and easily destroyed by oxidation at high temp. 14
Organic acids such
as citric acid, malic acid, tartaric acid,
etc these acids gives some function : 1. Fruit tartness and flavour 2. Slow down bacterial spoilage 3. Influence the colour of food
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Pigment
sources of colour classified into four major groups : Chlorophylls - oil soluble, bound to protein molecules - C alone is highly unstable (acid pH) - C changes becoming pheophytin (on heating), can be protected by addition alkali to the cooking or canning water
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Carotenoids - fat soluble - fairly resistant to heat, change in pH and water leaching - very sensitive to oxidation
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Flavonoids - water soluble 1. Anthocyanin shifting of color with pH violet/blue in alkaline or metal ions red in acid media 2. Anthoxanthin pH sensitives deeper yellow (in pH >8) and whiter yellow (in pH <6)
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Enzymes biological catalyst promote biochamical reaction Hidrolase (lipase, invertase, tannase, etc) oxidoreductase (peroxide, catalase, etc) Some properties : control the reaction associated of ripening responsible for changing of flavor, color, texture and nutritional properties activity of enzyme is characterized by an optimal temp and pH 19
Fresh - Kerusakan yg bisa terjadi ? - cara mencegah?
Minimally processes -
Faktor-faktor penyebab kerusakan? Cara mencegah atau mengatasi?
Fully processed food - Faktor-faktor yang mempengaruhi mutu? - Cara mempertahankan mutu dan mencegah kerusakannya ?
Ubi-ubian/roots/tubers
Nutritional aspects of root and tuber crops FW = fresh weight
Crop
Starch
Protein
Vitamin A
Vitamin C
% FW
% FW
mg/100g FW
mg/100g FW
Cassava
27-36
0.5-2.0
17
50
Potato
13-16
2.0
Trace
31
Sweet potato
18-28
1.0-2.5
900
35
Yam
18-25
2.5
117
24
Aroids
19-21
2.0
0-42
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Jenis ubi-ubian di Indonesia
• • • • • •
Talas Singkong Ubi Jalar Iles-iles Ganyong Garut
Sweet potato tubers
Sweet Potato – Ipomoea batatas
Sweet potato Nutritional composition Water 60-70% Carbohydrates 18-22% Proteins 0,6 – 0,8% Lipids 0,1 – 0,3% Ash 0,7 – 0,9 % Fiber 2 – 3 %
Sweet potato-contain the highest sugar and thiamin content as well as vitamin A, riboflavin, niacin, vitamin C and mineral (Fe, K, Na)
Roots/ tubers Anti nutritional composition Tripsin inhibitor Oligosakarida – penyebab flatulensi - gas H2 dan CO2
Sweet Potato - Processing Komponen spesifik : β karoten, vitamin E, vitamin C, vitamin B6, kalium, zat besi dan serat kasar, tidak mengandung lemak dan rendah natrium.
Manihot or Cassava – Manihot esculenta
Cassava Nutritional composition Water Carbohydrates Proteins Lipids Ash Fiber
Cassava AntiNutritional composition Produk
Kadar HCN (ppm)
Produk
Kadar HCN (ppm)
Ubi kayu segar 88,3-416,3 utuh
Kulit kering jemur 264,3-321,5
Daging umbi
34,3-301,3
Kulit
364,2-814,7
Ubi utuh kering 51,7-63,7 oven Daging ubi kering 23,7-31,3 oven
Ubi kering 23,1-41,6 jemur Daging ubi 17,3-26,7 kering jemur
Kulit kering oven
666,8-1250
Limbah ubi kayu 240 kering (kulit dan potongan umbi kecil)
Tuber – White Potato
Benefits of the Potato
Potato: Antinutritional Dalam umbi terdapat senyawa antinutrisi solanin and chaconin Secara umum senyawa alkaloid pada kentang disebut Solanin Konsentrasi bervariasi tergantung beberapa kondisi yaitu suhu, dan kelembaban, kualitas tanah, jenis pupuk, faktor stres pada tanaman (e.g. Serangan serangga, kerusakan karena mekanis dan sinar) Keberadaan magnesium dalam tanah akan meningkatkan senyawa alkaloid, sedangkan molybdenum dalam tanah akan menurunkan konsentrasi alkaloidnya .
Glycoalkaloids of potatoes (Solanum tuberosum, Solanaceae)
Produksi kentang adalah keempat terbesar diantara tanaman pangan seluruh dunia. Senyawa toksik glikoalkaloid terdapat pada semua jenis kentang Solanum tuberosum, dan juga pada sebagian besar spesies famili Solanaceae. Alkaloid ini disebut sebagai steroid glycoalkaloids (SGA), or pseudoalkaloids, Diklasifikasikan juga sebagai glukosida karena memiliki ikatan glukosida pada molekulnya.
Pada bagian parenkim pati pada umbi kentang terdapat sekitar 1% of solanin Glikoalkaloid adalah senyawa yang termostable, sehingga tidak dapat dihilangkan dengan pemasakan, penggorangan atau pengeringan dan hanya rusak pada suhu diatas 300°C. Tetapi proses pemanasan dengan perebusan akan menyebabkan alkaloid terlarut dalam air. Solanin – dalam ubi kentang segar berkulit konsentrasi solanin adalah lebih dari 100 mg/kg. Batas yang dapat dikonsumsi untuk alkaloid adalah 200 mg/kg. Tetapi pada kadar 150 mg/kg, akan timbul rasa pahit sehingga umumnya tidak dikonsumsi.. Glycoalkaloids terdapat dalam 1.5 mm ketebalan kulit.
Konjac/porang/iles-iles
Glucomannan Terdapat senyawa glucomannan yang merupakan serat pangan yang dapat diperoleh dari Amorphophallus konjac (Devil's Tongue). Glukomannan digunakan sebagai as a hunger suppressant karena memberikan rasa kenyang dengan dihasilkannya larutan yang sangat kental dalam lambung, hal ini juga mencegah penyerapan nutrient pada makanan. 1 gram polisakarida yang mudah larut ini dapat menyerap 200 ml air, sehingga dapat digunakan sebagai absorbent (pada diapers atau napkins)
Serealia/Grains
Grass Fruits/Cereals
What are Grains?? Bran 5% of kernel High fiber and mineral ash Contains some fat
Endosperm
83% of kernel High starch Contains protein Very low vitamin, mineral, and fat content
Germ 2-3% of kernel Rich in fat, protein, ash, and
vitamins Tiny embrio that will grow into a new plant
Nutrients in Grains Endosperm: karbohidrat kompleks, protein dan sejumlah kecil vitamin dan mineral.
Bran: tinggi serat, vitamin B dan mineral Germ: Vitamin B dan E, besi, zinc, and beberapa mineral, protein dan sejumlah lemak jenuh.
Cereal grains Karakteristik: • Cereal grains are essentially carbohydrate concentrates, the main nutrient is starch (600-700 g/kg d.m.) • Their protein content ranges from 80-120g/kg d.m., the protein is deficient in certain essential amino acids, like lysine and methionine • The germ contains more oil • The lipid content of wheat, barley, rye and oats is 10-30 g/kg, sorghum, maize and oats 30-60g/kg d.m.
• The fibre content depends on the presence of husks and hulls (barley, oats, rice: 50-200g/kg d.m.). Naked grains contains less fibre (wheat, corn, rye: 23-30g/kg d.m.) • High phosphorus content in the aleuronic layer, but it is present as poorly digestible phytic acid •They are good sources of vitamin E and thiamine (B1)
Whole Grains
Cereal grains with endosperm, germ, and bran present in same relative proportions as found in nature
Whole grain consumption associated with reduced risk of ◦ ◦ ◦ ◦
Cancer Cardiovascular heart disease Diabetes Obesity
Grain Processing All grains must be processed, and this begins with removal of the outer husk. •Whole Grain •The entire edible grain kernel is used, the resulting product contains most of the kernel’s original nutrients. Examples: whole wheat flour, whole-grain cereals
When the bran and germ are removed, many nutrients are lost. Examples include white bread and most breakfast cereals. When this happens, the grain products are enriched and fortified.
•Enrichment: a process in which some nutrients lost as a result of processing are added back to the product. •Fortified: a process of adding 10% or more of the Daily Value for a specific nutrient to a product.
Grain Processing
Most grains are low in some essential amino acids. To get a complete protein, it is necessary to also eat something else, such as a legume. White flour, corn starch, white rice: just the endosperm, with the bran and germ removed. Brown rice, whole wheat flower, popcorn = the whole grain including bran and germ. ◦ It contains much more protein and other nutrients than the endosperm alone. ◦ But, it spoils faster due to fats in the germ, and bread made with whole flower doesn’t rise as well.
Barley
Like all grains, barley was originally toasted or eaten as a porridge. But, very early, people learned how to make beer from barley. Laws regulating beer are found in the Code of Hammurabi (about 1790 BC, Babylonian Empire). ◦ Most water is contaminated with microorganisms that cause disease, especially before people knew about microorganisms. ◦ Making beer sterilizes the water: it was much safer and healthier to drink beer than water. Also the reason for coffee and tea
