الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 155 |  |  |
| | | from | 155 | | |
Abstract
objective of this study was to determine the physicochemical properties of the native starches -isolated from one cultivar of Taro obtained from the local market, two cultivars of corn: Hi-Tech 2031 and Giza TWC 352 Y, two cultivars of wheat: Durum Beni Suef 1 and Bread wheat Misr 1, and finally two cultivars of potato: Sponta and Lady Rosetta-, and to compare & characterize their physicochemical properties
Recently, it has been reported that starches isolated from different plant cultivars have different physicochemical properties that could enhance different aspects of biological and industrial applications
Native starches are suites to a wide variety of applications, however, it appeared necessary to identify the physicochemical characteristics to meet the exact need required in industrial and commercial applications.
Till the moment, no single report was found discussing the isolation and physicochemical characterization of starches isolated from wide varieties of Egyptian plant cultivars.
All these facts encourage us to select some Egyptian crops of different varieties, isolate their starches and study their physicochemical properties.
The current work involves isolation of starches from different crops of different cultivars and studying the physicochemical properties of these starches. from one taro cultivar (Local), two wheat cultivars (Durum Beni Suef 1 and Bread Wheat Misr 1), two corn cultivars (Giza TWC 352 Y and Hi-Tech 2031) and two potato cultivars (Sponta and Lady Rosetta), different starches were separately isolated and subjected for physicochemical investigation.
The physicochemical studies done involved; proximate analysis (contents of ash, fat, moisture, protein and total carbohydrate).
Other analyses like total organic matter (TOM), total organic carbon (TOC) were also quantified.
Different elements in the isolated starches were quantified using either Graphite Technique or inductively coupled plasma technique (ICP), where contents of arsenic (As), cadmium (Cd), chromium (Cr), lead (Pb), nickel (Ni), selenium (Se), tin (Sn), cobalt (Co), antimony (Sb), molybdenum (Mo), copper (Cu), manganese (Mn) were quantified using graphite technique, while, contents of calcium (Ca), iron (Fe), zinc (Zn), potassium (K), sodium (Na), phosphorus (P) and magnesium (Mg) were quantified using ICP technique.
The degree of hydrolysis of the isolated starches as well as the amylose-amylopectin profile, pH values, water binding capacity (WBC) solubility and swelling power at different temperatures were also carried out.
Spectroscopic studies, like Fourier transform infrared spectrometry (FT-IR) were achieved to study the characteristic bands of each cultivar, like OH bands, aliphatic CH stretching frequencies, beside the finger print region of each cultivar.
The X-ray diffraction pattern (XRD) of the crystal structure of the isolated starches were studied to assure the crystallinity type of the starches (A or B types).
The ash content among all isolated starches ranged from 0.01% [wheat (Bread Wheat Misr 1) and corn (Giza TWC 352 Y)] to 0.046% [Taro (Local)]. The values of the ash contents of the studied starches increase ascendingly, following order: wheat (Bread WheatMisr 1; 0.01%) / and or Corn (Giza TWC 352 Y; 0.01%) < potato (Sponta; 0.018%) < wheat (Durum Beni Suef 1; 0.026%) < Corn (Hi-Tech 2031; 0.027%) < Potato (Lady Rosetta; 0.04%) < Taro (Local; 0.046%).
The Fat content ranged from 0.26% (taro; Local) to 0.79% (wheat; Bread Wheat Misr 1) following the ascending order: taro (Local; 0.26%) < potato (Sponta; 0.33%) < potato (Lady Rosetta; 0.36) < corn (Hi-Tech 2031; 0.55%) < corn (Giza TWC 352 Y; 0.62%) < wheat (Durum Beni Suef 1; 0.64% < wheat (Bread Wheat Misr 1; 0.79%).
The moisture content ranged from 6.88% (corn; Hi-Tech 2031) to 9.69% (wheat; Bread Wheat Misr 1) following the ascending order; corn (Hi-Tech 2031 cultivar; 6.88%) < taro (Local; 7.96%) < potato (Sponta; 8.52%) < wheat (Durum Beni Suef 1; 8.86%) < corn (Giza TWC 352 Y; 9.006%) < potato (Lady Rosetta; 9.28%) < wheat (Bread Wheat Misr 1; 9.69%).
The protein content ranged from 0.49% (corn; Giza TWC 352 Y) to 3.75% (potato; Sponta) following the ascending order; corn (Giza TWC 352 Y; 0.49%) < wheat (Bread Wheat Misr 1; 0.55%) < taro (Local; 0.73%) < potato (Lady Rosetta; 1.25%) < corn (Hi-Tech 2031; 3.2%) < wheat (Durum Beni Suef 1; 3.72%) < potato (Sponta; 3.75%).
The total carbohydrate content ranged from 86.75% (wheat; Durum Beni Suef 1) to 91% (taro; Local) following the ascending order; wheat (Durum Beni Suef 1; 86.75%) < potato (Sponta; 87.38%) < wheat (Bread Wheat Misr 1; 88.96%) < potato (Lady Rosetta; 89.07%) < corn (Hi-Tech 2031; 89.34%) < corn (Giza TWC 352 Y; 89.78%) < taro (Local; 91%).
The total organic matter content (TOM) ranged from ranged from 90.3% to 93.1%, following the ascending order; wheat (Bread Wheat Misr 1; 90.30%) < potato (Lady Rosetta; 90.68%) < corn (Giza TWC 352 Y; 90.99%) < wheat (Durum Beni Suef 1; 91.12%) < potato (Sponta; 91.46%) < taro (Local; 92.00%) < corn (Hi-Tech 2031; 93.10%).
Different undesired heavy metals as well as nutritive elements were quantified. chromium concentration ranged from 1045 to 1231 ppb following the ascending order; potato (Lady Rosetta; 1045 ppb) < wheat (Bread Wheat Misr 1; 1090 ppb) < corn (Hi-Tech 2031; 1096 ppb) < corn (Giza TWC 352 Y; 1127 ppb) < potato (Sponta; 1155 ppb) < wheat (Durum Beni Suef 1; 1196 ppb) < taro (Local; 1231 ppb).
Nickel (Ni) concentration ranged from 3076 to 5090 ppb following the ascending order; wheat (Durum Beni Suef 1; 3076 ppb) < corn (Hi-Tech 2031; 3131 ppb) < wheat (Bread Wheat Misr 1; 3270 ppb) < corn (Giza TWC 352 Y; 3399 ppb) < potato (Sponta; 3638 ppb) < taro (Local; 4707 ppb) < potato (Lady Rosetta; 5090 ppb).
Arsenic ranged from 359.2 to 1256 ppb following the ascending order wheat (Bread Wheat Misr 1; 359.2 ppb) < potato (Lady Rosetta; 516.4 ppb) < potato (Sponta; 579.7 ppb) < wheat (Durum Beni Suef 1; 974 ppb) < corn (Giza TWC 352 Y; 1043 ppb) < taro (Local; 1179 ppb) < corn (Hi-Tech 2031; 1256 ppb).
Lead (Pb) concentration ranged from 1017 to 3050 ppb following the ascending order; wheat (Bread Wheat Misr 1; 1017 ppb) < taro (Local; 1204 ppb) < wheat (Durum Beni Suef 1; 1402 ppb) < potato (Sponta; 1732 ppb) < potato (Lady Rosetta; 2148 ppb) < corn (Hi-Tech 2031; 2935 ppb) < corn (Giza TWC 352 Y; 3050 ppb).
Cadmium (Cd) concentration ranged from 992.6 to 1907 ppb following the ascending order; wheat (Bread Wheat Misr 1; 992.6 ppb) < wheat (Durum Beni Suef 1; 995.5 ppb) < potato (Sponta; 1026 ppb) < potato (Lady Rosetta; 1037 ppb) < corn (Hi-Tech 2031; 1067 ppb) < corn (Giza TWC 352 Y; 1100 ppb) < taro (Local; 1907 ppb).
Sodium (Na) concentration ranged from 32.66 to 142.9 ppm following the ascending order; wheat (Durum Beni Suef 1; 32.66 ppm) < potato (Sponta; 69.69 ppm) < taro (Local; 72.49 ppm) < wheat (Bread Wheat Misr 1; 79.8 ppm) < corn (Giza TWC 352 Y; 114.3 ppm) < corn (Hi-Tech 2031; 115.9 ppm) < potato (Lady Rosetta; 142.9 ppm).
Potassium (K) concentration ranged from 0.05 to 13.14 ppm following the ascending order; potato (Lady Rosetta; 0.05 ppm) < potato (Sponta; 0.998 ppm) < wheat (Durum Beni Suef 1; 1.222 ppm) < taro (Local; 3.979 ppm) < wheat (Bread Wheat Misr 1; 4.107 ppm) < corn (Hi-Tech 2031; 9.008 ppm) < corn (Giza TWC 352 Y; 13.14 ppm).
Phosphorus (P) concentration ranged from 4.94 to 31.78 ppm following the ascending order; corn (Giza TWC 352 Y; 4.94 ppm) < corn (Hi-Tech 2031; 7.84 ppm) < taro (Local; 8.07 ppm) < wheat (Bread Wheat Misr 1; 16 ppm) < potato (Lady Rosetta; 16.37 ppm) < wheat (Durum Beni Suef 1; 19.29 ppm) < potato (Sponta; 31.78 ppm).
Magnesium (Mg) concentration ranged from 2.79 to 75.39 ppm following the ascending order; potato (Sponta; 2.79 ppm) < potato (Lady Rosetta; 6.531 ppm) < taro (Local; 16.33 ppm) < corn (Hi-Tech 2031; 16.98 ppm) < corn (Giza TWC 352 Y; 22.51 ppm) < wheat (Bread Wheat Misr 1; 52.41 ppm) < wheat (Durum Beni Suef 1; 75.39 ppm).
The calcium (Ca) concentration ranged from 1.096 to 331.3 ppm following the ascending order; corn (Hi-Tech 2031; 1.096 ppm) < corn (Giza TWC 352 Y; 3.66 ppm) < potato (Sponta; 11.48 ppm) < wheat (Bread Wheat Misr 1; 39.02 ppm) < taro (Local; 56.15 ppm) < wheat (Durum Beni Suef 1; 63.97 ppm) < potato (Lady Rosetta; 331.3 ppm).
Manganese (Mn) concentration ranged from 31 to 1235 ppb following the ascending order; wheat (Bread Wheat Misr 1; 31 ppb) < wheat (Durum Beni Suef 1; 74.2 ppb) < taro (Local; 90.8 ppb) < corn (Giza TWC 352 Y; 106.4 ppb) < potato (Sponta; 289.4 ppb) < corn (Hi-Tech 2031; 553.5 ppb) < potato (Lady Rosetta; 1235 ppb).
Iron (Fe) concentration ranged from 0.127 to 4.829 ppm following the ascending order; potato (Sponta; 0.127 ppm) < potato (Lady Rosetta; 0.194 ppm) < taro (Local; 0.899 ppm) < wheat (Bread Wheat Misr 1; 1.041 ppm) < wheat (Durum Beni Suef 1; 3.375 ppm) < corn (Giza TWC 352 Y; 4.532 ppm) < corn (Hi-Tech 2031; 4.829 ppm).
Cobalt (Co) concentration ranged from 207.7 to 490.6 ppb following the ascending order; corn (Hi-Tech 2031; 207.7 ppb) < wheat (Durum Beni Suef 1; 246.4 ppb) < potato (Sponta; 270 ppb) < wheat (Bread Wheat Misr 1; 271.1 ppb) < potato (Lady Rosetta; 410 ppb) < taro (Local; 415.1 ppb) < corn (Giza TWC 352 Y; 490.6 ppb).
Copper (Cu) concentration ranged from 75.84 to 21840 ppb following the ascending order; taro (Local; 75.84 ppb) < wheat (Bread Wheat Misr 1; 380.8 ppb) < potato (Lady Rosetta; 665.9 ppb) < potato (Sponta; 844.1 ppb) < corn (Giza TWC 352 Y; 5841 ppb) < wheat (Durum Beni Suef 1; 10180 ppb) < corn (Hi-Tech 2031; 21840 ppb).
Selenium (Se) concentration ranged from 335.7 to 1689 ppm following the ascending order; taro (Local; 335.7 ppm) < wheat (Bread Wheat Misr 1; 1053 ppm) < potato (Sponta; 1275 ppm) < corn (Giza TWC 352 Y; 1299 ppm) < corn (Hi-Tech 2031; 1535 ppm) < wheat (Durum Beni Suef 1; 1540 ppm) < potato (Lady Rosetta; 1689 ppm).
Zinc (Zn) concentration ranged from 17.51 to 276.1 ppm following the ascending order; potato (Lady Rosetta; 17.51 ppm) < potato (Sponta; 25.63 ppm) < taro (Local; 86.45 ppm) < wheat (Bread Wheat Misr 1; 91.23 ppm) < wheat (Durum Beni Suef 1; 104 ppm) < corn (Hi-Tech 2031; 115.3 ppm) < corn (Giza TWC 352 Y; 276.1 ppm).
Molybdenum (Mo) concentration ranged from 1742 to 18490 ppb following the ascending order; potato (Sponta; 1742 ppb) < corn (Hi-Tech 2031; 1876 ppb) < potato (Lady Rosetta; 2064 ppb) < corn (Giza TWC 352 Y; 2190 ppb) < wheat (Durum Beni Suef 1; 15150 ppb) < wheat (Bread Wheat Misr 1; 15570 ppb) < taro (Local; 18490 ppb).
Tin (Sn) concentration ranged from 781.9 to 2376 ppb following the ascending order; wheat (Bread Wheat Misr 1; 781.9 ppb) < wheat (Durum Beni Suef 1; 992.7 ppb) < potato (Lady Rosetta; 1011 ppb) < corn (Giza TWC 352 Y; 1093 ppb) < potato (Sponta; 1276 ppb) < taro (Local; 1391 ppb) < corn (Hi-Tech 2031; 2376 ppb).
Antimony (Sb) concentration ranged from 912.7 to 1040 ppb following the ascending order; taro (Local; 912.7 ppb) < wheat (Durum Beni Suef 1; 978.7ppb) < corn (Hi-Tech 2031; 995.3 ppb) < potato (Sponta; 1017 ppb) < potato (Lady Rosetta; 1020 ppb) < corn (Giza TWC 352 Y; 1025 ppb) < wheat (Bread Wheat Misr 1; 1040 ppb).
As starch is a mixture of two main components: amylose and amylopectin, the amylose and amylopectin pattern of the isolated starches from different crop cultivars were quantified.
Thus, Amylose concentration ranged from 22.76 to 46.51 % following the ascending order; taro (Local; 22.76%) < potato (Sponta; 26.8%) < corn (Hi-Tech 2031; 29.44%) < wheat (Durum Beni Suef 1; 29.92%) < corn (Giza TWC 352 Y; 31.01%) < potato (Lady Rosetta; 40.56%) < wheat (Bread Wheat Misr1; 46.51%), while amylopectin concentration ranged from 42.45 to 68.24 following the ascending order; wheat (Bread Wheat Misr 1; 42.45%) < potato (Lady Rosetta; 48.51%) < wheat (Durum Beni Suef 1; 56.83%) < corn (Giza TWC 352 Y; 58.77%) < corn (Hi-Tech 2031; 59.9%) < potato (Sponta; 60.58%) < taro (Local; 68.24%).
pH values of the isolated starches were found to be dependent on the amylose-amylopectin profile. Thus, the lower pH values were found to be for those starches of highest amylose conents, potato (Sponta) and taro (Local), while the highest pH values were found to be in wheat and corn solutions.
The values of pH of the isolated starch slurries ranged from 2.45 to 3.96 following the ascending order; potato (Sponta; 2.45) < Taro (Local; 2.47) < potato (Lady Rosetta; 2.89) < wheat (Durum Beni Suef 1; 3.11) < wheat (Bread Wheat Misr 1; 3.45) < corn (Hi-Tech 2031; 3.53) < corn (Giza TWC 352 Y; 3.96). All the measured pH are considered to be acidic (pH < 7).
The isolated starches were heated at reflux temperature in diluted ethanolic sodium hydroxide solution for 15 minutes. The resistant starch ranged from 30.07 to 33.34%. The resistivity of starches towards alkaline hydrolysis increases in the ascending order; Wheat (Durum Beni Suef 1; 30.07%) < Potato (Sponta; 30.58%) < Wheat (Bread Wheat Misr 1; 31.81%) < Potato (Lady Rosetta; 31.9%) < Corn (Hi-Tech 2031; 32.1%) < Corn (Giza TWC 352 Y; 32.43%) < Taro (Local; 33.34%).
The water binding capacity (WBC) of the studied isolated starches were quantified. Thus, the water binding capacity of these starches ranged from 70.16 to 123.67% in the ascending order; potato (Lady Rosetta; 70.16%) < wheat (Bread Wheat Misr 1; 62.6%) < taro (Local; 70.24%) < corn (Giza TWC 352 Y; 73.66%) < Potato (Sponta; 80.67%) < Corn (Hi-Tech 2031; 99.73%) < Wheat (Durum Beni Suef 1; 123.67%).
Solubility of the isolated starches was studied at three different temperatures 30 oC, 60 oC and 95oC, respectively. At 30 oC, potato (Sponta) and taro (Local) recorded the highest solubility, being, 40.99 and 26.82, respectively. Raising temoerature to 100 oC enhanced the solubility of all starches, especially, potato (Sponta) and taro (Local) as they recorded full solubility (100%) at this temperature. At 95oC, taro (Local), wheat (Bread Wheat Misr 1), corn (Hi-Tech 2031), potato (Sponta) and potato (Lady Rosetta) recorded 100% solubility.
The swelling power (g/g) of the isolated starches was studied at 30 oC, 60 oC and 95 oC. At 30oC, the swelling power of different isolated starches ranged from 5.47 to 6.19 in the ascending order; corn (Giza TWC 352 Y; 5.47 g/g) < taro (Local; 5.77 g/g) < potato (Sponta; 5.79 g/g) < wheat (Bread Wheat Misr 1; 6.07 g/g) < potato (Lady Rosetta; 6.19 g/g) < corn (Hi-Tech 2031; 6.55 g/g) < Wheat (Durum Beni Suef 1; 6.60 g/g). Except taro (local) and potato (Sponta), increasing temperature (to 60oC or 95o) led to an increase in the swelling power. Studying the swelling power in comparison with the water binding capacity led to interesting finding. The wheat cultivar, Durum Beni Suef 1, of highest water binding capacity (123.67%) among all the studied cultivars, recorded the highest swelling power, under all studied heat temperatures (6.6, 9.95 and 14.5 g/g at 30, 60 and 95oC, respectively).
The FT-IR Spectrum of each isolated starch was obtained and the full spectra were compared to each other in the region 4000-400 cm-1. The OH frequency region for the isolated starches ranged from 3600-3000 cm-1 due to the presence of OH group, while CH stretching frequencies ranged from 2800-3000.
The X-ray study of the isolated starches was made to show their crystallinity and the obtained data revealed that they are all of B type