function of the starch granule in a

function of the starch granule in a plant; if the energy is dissolved too early,
it is not much of an energy store.
Starch granules are not homogeneous with regard to the distribution of
water, and the water content at certain locations (e.g., at the site of the
crystallites during melting) is not known. Some of the water is located in the
TABLE 10.3
Irreversible Events Occurring During Gelatinization and the Onset
(To
) and Conclusion (Tc
) Temperature for Various Water Contents
Starch
Starch
Content (%) To
(°C) Tc
(°C) Ref.
Appearance of DSC endotherm
Rice, waxy 20
50
60
60
78
93
82
Rice, normal 20
50
60
61
77
92
82
Maize, waxy 25 67.2 — 83
Maize, normal 25 69.2 — 83
Amylomaize V 25 70.1 — 83
Disappearance of birefringence
Maize Excess water 49 67 84
Wheat 5
Excess water
52
50
62
54
85
86
Barley Excess water 55.5 65 87
Barley, high-amylose Excess water 58.5 69 87
Barley, waxy Excess water 58 67.5 87
Disappearance of crystallinity
Wheat 5 49.3 59.0 45
Potato 5

Hasil (Bahasa Indonesia) 1:

function of the starch granule in a plant; if the energy is dissolved too early,it is not much of an energy store.Starch granules are not homogeneous with regard to the distribution ofwater, and the water content at certain locations (e.g., at the site of thecrystallites during melting) is not known. Some of the water is located in theTABLE 10.3Irreversible Events Occurring During Gelatinization and the Onset (To) and Conclusion (Tc) Temperature for Various Water ContentsStarchStarchContent (%) To(°C) Tc(°C) Ref.Appearance of DSC endothermRice, waxy 20506060789382Rice, normal 20506061779282Maize, waxy 25 67.2 — 83Maize, normal 25 69.2 — 83Amylomaize V 25 70.1 — 83Disappearance of birefringenceMaize Excess water 49 67 84Wheat 5Excess water525062548586Barley Excess water 55.5 65 87Barley, high-amylose Excess water 58.5 69 87Barley, waxy Excess water 58 67.5 87Disappearance of crystallinityWheat 5 49.3 59.0 45Potato 5 <57.4 67.0 45Maize 5 60.2 71.0 45Maize, waxy 5 64.5 71.0 45SwellingWheat Excess water 48 — 29Barley, waxy Excess water 45 — 29Barley, normal Excess water 45 — 29SolubilityWheat Excess water 50 — 29Barley, waxy Excess water 40 — 29Barley, normal Excess water 40 — 29© 2006 by Taylor & Francis Group, LLCStarch: Physicochemical and Functional Aspects 405amorphous parts, but some water is also present in the unit cells of thecrystallites [37]. If the starch is dried to complete dryness, the x-ray diffractionpattern disappears [42]. With NMR or DSC it can be observed that a proportionof the water will not freeze during the experimental conditions (i.e., at temperatures at or below –50°C). These values are in the range of 0.25 to 0.40 gwater per g starch [89–91].When dry starch granules are placed in water, a small amount of wateris absorbed. This is an exothermic process, and the heat of immersiondecreases to zero at a water content of 0.18 g water per g dry starch for wheatand 0.20 g water per g dry starch for potato [42]. These values correspondto the water content of starch in equilibrium with ambient air, which is around13% (w/w) for wheat and 18 to 22% (w/w) for potato [92]. Expressed in anotherway, this is 1.5 water molecules per anhydrous glucose unit. Potato starchgranules in equilibrium with excess water have a water content of 0.54 g waterper g dry starch (i.e., 5 water molecules per anhydrous glucose unit) [80].If the temperature is increased, the amount of absorbed water increases.Up until a certain temperature (the onset of gelatinization), the water uptakeis reversible, but after that the changes are irreversible. For potato starch, thevolume of swollen granules can be almost 200 ml/g dry starch [93]. It shouldbe pointed out, however, that it is not the amount of water that is importantbut the amount of solvent [93a].10.3.2.1 Loss of BirefringenceIn polarized light, ungelatinized starch granules show birefringence, and atypical so-called Maltese cross is more or less evident [18]. When Tois reached,order is lost in the starch granules, although not necessarily order at thecrystalline level. One of the most common methods for determining the gelatinization temperature range is to follow the loss of birefringence in excesswater [94]. Viewing a starch-containing food sample in polarized light in amicroscope might thus give some indication of the heat treatment that thesample has undergone [95]. The loss of birefringence occurs over a broadertemperature interval when the water content is decreased. For wheat starchwith 29% (w/w) water heated to 132°C, birefringence has still been detected[96], and with a water content below 8% not even heating to 232°C destroyedthe birefringence [97].10.3.2.2 Loss of CrystallinityThe loss of crystalline order during heating is observed in x-ray diffraction.The diffraction pattern disappears, and eventually a pattern indicative of acompletely amorphous material is obtained [98]. In cereal starches, the Vpattern (i.e., the x-ray diffraction pattern related to the amylose–lipid complex)© 2006 by Taylor & Francis Group, LLCthe birefringence begins to disappear (see Table 10.3). This loss indicates that

Hasil (Bahasa Indonesia) 2:

fungsi dari granul pati dalam tanaman; jika energi dibubarkan terlalu dini,
itu tidak banyak menyimpan energi.
butiran pati tidak homogen berkaitan dengan distribusi
air, dan kadar air di lokasi-lokasi tertentu (misalnya, di lokasi yang
kristalit selama peleburan) adalah tidak diketahui. Beberapa air terletak di
TABEL 10.3
Events ireversibel Terjadi Selama Gelatinisasi dan Onset
(Untuk
) dan Kesimpulan (Tc
) Suhu untuk Berbagai Isi Air
Pati
Pati
Content (%) Untuk
(° C) Tc
(° C) Ref.
Penampilan DSC endoterm
Beras, lilin 20
50
60
60
78
93
82
Beras, normal 20
50
60
61
77
92
82
Jagung, lilin 25 67,2-83
Jagung, normal 25 69,2-83
Amylomaize V 25 70,1-83
Penghilangan birefringence
Jagung Kelebihan air 49 67 84
Gandum 5
Kelebihan air
52
50
62
54
85
86
Barley Kelebihan air 55,5 65 87
Barley, Kelebihan air tinggi amilosa 58,5 69 87
Barley, Kelebihan air berlilin 58 67,5 87
Penghilangan kristalinitas
Wheat 5 49,3 59,0 45
Potato 5 <57,4 67,0 45
Jagung 5 60.2 71.0 45
Jagung, lilin 5 64.5 71.0 45
Pembengkakan
Wheat Kelebihan air 48-29
Barley, lilin Kelebihan air 45-29
Barley, Kelebihan air yang normal 45-29
Kelarutan
Wheat Kelebihan air 50-29
Barley, Kelebihan air lilin 40-29
Barley, Kelebihan air yang normal 40-29
© 2006 oleh Taylor & Francis Group, LLC
Pati: fisiko dan Aspek Fungsional 405
bagian amorf, tetapi beberapa air juga hadir dalam sel unit
kristal [37]. Jika pati dikeringkan untuk menyelesaikan kekeringan, difraksi x-ray
pola menghilang [42]. Dengan NMR atau DSC dapat diamati bahwa proporsi
air tidak akan membeku selama kondisi eksperimental (yaitu, pada suhu pada atau di bawah -50 ° C). Nilai-nilai ini berada di kisaran 0,25-0,40 g
air per gram tepung [89-91].
Ketika granula pati kering ditempatkan dalam air, sejumlah kecil air
yang diserap. Ini adalah proses eksotermik, dan panas perendaman
menurun hingga nol pada kandungan air 0,18 g air per g tepung kering untuk gandum
dan 0,20 g air per g tepung kering untuk kentang [42]. Nilai-nilai ini sesuai
dengan kadar air pati dalam kesetimbangan dengan udara ambien, yaitu sekitar
13% (b / b) untuk gandum dan 18 sampai 22% (b / b) untuk kentang [92]. Disajikan dalam lain
cara, ini adalah 1,5 molekul air per unit glukosa anhidrat. Tepung kentang
granula dalam kesetimbangan dengan kelebihan air memiliki kadar air 0.54 g air
per gram pati kering (yaitu, 5 molekul air per unit glukosa anhidrat) [80].
Jika suhu meningkat, jumlah air meningkat diserap.
Sampai suhu tertentu (awal gelatinisasi), penyerapan air
adalah reversibel, tapi setelah itu perubahan yang ireversibel. Untuk tepung kentang, yang
volume butiran bengkak dapat hampir 200 ml / g pati kering [93]. Perlu
ditekankan, bagaimanapun, bahwa itu bukan jumlah air yang penting
tetapi jumlah pelarut [93a].
10.3.2.1 Kehilangan Birefringence
Dalam cahaya terpolarisasi, granula pati ungelatinized menunjukkan birefringence, dan
khas yang disebut Salib Malta adalah lebih atau kurang jelas [18]. Ketika Untuk
tercapai,
agar hilang dalam granula pati, meskipun tidak selalu memesan di
tingkat kristal. Salah satu metode yang paling umum untuk menentukan kisaran suhu gelatinisasi adalah mengikuti hilangnya birefringence lebih
air [94]. Melihat sampel makanan pati yang mengandung cahaya terpolarisasi dalam
mikroskop sehingga mungkin memberikan beberapa indikasi perlakuan panas bahwa
sampel telah mengalami [95]. Hilangnya birefringence terjadi selama lebih luas
selang suhu ketika kadar air menurun. Untuk tepung gandum
dengan 29% (b / b) air dipanaskan sampai 132 ° C, birefringence masih terdeteksi
[96], dan dengan kadar air di bawah 8% bahkan tidak pemanasan sampai 232 ° C menghancurkan
birefringence [97].
10.3 .2.2 Kehilangan Kristalinitas
Hilangnya urutan kristal selama pemanasan diamati dalam difraksi sinar-x.
Pola difraksi menghilang, dan akhirnya pola indikasi dari
bahan sepenuhnya amorf diperoleh [98]. Dalam pati sereal, yang Vpattern (yaitu, pola difraksi sinar-x yang terkait dengan kompleks amilosa-lipid)
© 2006 oleh Taylor & Francis Group, LLC
birefringence mulai menghilang (lihat Tabel 10.3). Kerugian ini menunjukkan bahwa