Wheat Starch

• CAS No.: 9005-25-8
• EINECS: 9002-18-0
• Resource: Natural
• Transport Package: Large
• Specification: large
• Trademark: china
• Model NO.: E1422
• Origin: China
• HS Code: 110811
• Production Capacity: 5000kg/Year

Product Description

Wheat starch is the major component of pasta and represents about 70% of its weight. However, wheat protein is the major determinant of spaghetti cooking quality and starch plays a secondary role.^509-511 Starch functionality in pasta is somewhat ignored, as evidenced from the scant information available in the literature. Delcour et al.⁵¹² provided insight into the role of durum gluten and starch interactions in spaghetti quality using fractionation and reconstitution experiments.

Wheat starch is the major component of pasta and represents about 70% of its weight. However, wheat protein is the major determinant of spaghetti cooking quality and starch plays a secondary role.^509-511 Starch functionality in pasta is somewhat ignored, as evidenced from the scant information available in the literature. Delcour et al.⁵¹² provided insight into the role of durum gluten and starch interactions in spaghetti quality using fractionation and reconstitution experiments.

The effect of spaghetti processing and cooking on the starch component of semolina or spaghetti has been investigated. Loss of semolina shape during extrusion was shown by microscopic examination.⁵¹³ Matsuo et al.⁵¹⁴ found an alignment of starch granules in the direction of flow for the material taken at the first kneading plate of the pasta extruder. In the extruded spaghetti, granules are embedded within a protein matrix and those granules on the surface of spaghetti strands are coated with a smooth protein film. Examination by amylography of starch isolated from semolina or raw spaghetti revealed that semolina starch has a higher peak viscosity than spaghetti starch.⁵¹⁵ The different profile may be attributed to an annealing process or to the presence of damaged starch in spaghetti.

Wheat starch undergoes changes during the drying of spaghetti, especially when high temperature or ultra high temperature drying cycles are employed. High temperature drying caused modifications in the starch that significantly improved spaghetti cooking quality.⁵¹⁶ It was also observed that the amount of resistant starch significantly increased with high temperature treatment.⁵¹⁷ Furthermore, the starch isolated from the spaghetti exhibited a higher gelatinization temperature than the starch isolated from semolina.^517,518 Results of the studies on the effect of high temperature drying of spaghetti on starch gelatinization range, enthalpy of gelatinization and paste viscosity have been inconsistent.^517-520

Water penetration during the cooking of spaghetti is mainly a function of protein content. Starch gelatinization takes place in an inward direction and occurs at a rapid rate at a low protein concentration.^521,522 When viewed by scanning electron microscopy, cooked spaghetti exhibits a filamentous network near the outer surface that is a starch-coated protein network interconnected by starch fibrils.⁵²³ Resmini and Pagani⁵²⁴ reported a physical competition between protein coagulation into a continuous network and starch swelling and gelatinization during cooking of pasta. They postulated that, if protein coagulation prevails, starch particles will be trapped in the protein network, promoting firmness in pasta. If starch swelling and gelatinization prevail, the protein will coagulate in discrete masses rather than a continuous framework, resulting in soft and sticky pasta.

Starch changes during cooking of pasta are reported to vary from a hydration-driven gelatinization process in the outer layer to a heat-induced crystallite melting in the center.⁵²⁵ It is speculated that both the state of the starch and the surface structure contribute to the development of the elastic texture and stickiness of pasta. Interactions between starch and the surrounding protein matrix are evident in the outer and intermediate layer. In the center of cooked pasta, wheat starch granules retain their shape due to limited water diffusion, and the protein network remains dense.

Interchange of starch isolated from durum wheat and a hard red spring wheat had little effect on macaroni cooked weight, cooking water residue or firmness of cooked macaroni.⁵²⁶ The importance of amylose content in determining spaghetti cooking quality has been emphasized.⁵²⁷ Strands of cooked spaghetti made with low-amylose starch lacked resilience. Blends of gluten and non-wheat starches, such as waxy barley or waxy maize starches, resulted in spaghetti of poor cooking quality. By contrast, normal barley starch appeared to impart better cooking quality compared to other starches. It was speculated that other starch properties may impart better cooking quality to spaghetti once a certain level of amylose is present. In a reconstitution study, the optimum level of amylose was determined to be 32-44%.⁵²⁸ This amylose range yielded an extensible dough with increased spaghetti firmness and decreased water absorption. Total absence of amylose is detrimental, as confirmed in a reconstitution study where waxy wheat starch yielded poor quality spaghetti, judging from the decreased firmness and increased stickiness of the cooked spaghetti.⁵²⁹ In a related study, waxy durum wheat produced softer pasta with higher cooking loss than pasta made from traditional durum wheat cultivars.⁵³⁰

Nelson⁵³¹ investigated the properties of spaghetti made from blends of modified starch and semolina. Addition of up to 10% of commercially-modified starches from normal corn, waxy maize and tapioca starches, and laboratory-modified durum starch did not adversely affect spaghetti color and strand diameter. Firmness scores decreased as the percentage of starch in the blend increased. The level of starch added did not significantly affect spaghetti cooked weight and cooking loss. The type of commercially modified starch was found to have a significant effect on spaghetti cooked weight, but the type of modified durum starch did not significantly affect cooked weight or cooking loss. Using a reconstitution approach, small granule wheat starch imparted the highest cooked spaghetti firmness when added at 10-15% above the level normally found in durum wheat starch.⁵²⁸

Wheat noodles are consumed in large amounts in China, Japan, Korea, Malaysia, Taiwan, Singapore, Hong Kong and the Philippines.⁵⁰⁹ Oriental wheat noodles may be divided broadly into two classes: the Japanese white salted noodle; and the Chinese (Cantonese) yellow alkaline noodle. The first class is made from wheat flour (100 parts), water (35 parts) and table salt (1-2 parts); whereas the second class is made by replacing table salt with a mixture of sodium and potassium carbonates, often referred to as 'kansui.' Within the two classes, the five popular types of noodles are: raw; wet (boiled); dried; instant fried; and steamed and dried.^509,532,533

Because wheat flour, which comprises 70-75% starch, accounts for >95% of the dry solids in Oriental noodles, it is not surprising that the quality of noodles varies with starch properties.⁵³⁴ Quality differences of Chinese yellow noodles produced from Australian and US wheats are attributable to their starch properties.⁵³⁵ The water-holding capacity of starch was strongly correlated with the viscoelastic properties of Japanese noodles.⁵³⁶ Numerous researchers have provided evidence that moderately high swelling wheat starch in flour is important to the quality of Japanese salt noodles.^{313,534,537-549} By contrast, wheat flours with low-swelling starch are preferred for alkaline noodles in Japan.⁵⁵⁰

Nagao et al.⁵³⁷ were the first to report that good Japanese salt noodle flour from Australian standard white wheat gave a relatively low amylograph pasting temperature and a high pasting peak, which was later confirmed by Moss.⁵³⁸ Oda et al.⁵³⁹ reported that the eating quality of Japanese salt (udon) noodles correlated positively with rapid swelling of the starch in the amylograph. Others⁵⁴¹ showed that the starch from Australian standard white wheat flour gave a low pasting temperature and a relatively high paste consistency, and that the Australian standard white wheat starch had a higher swelling power compared to the starch from a representative Japanese wheat. High swelling of starch in flour also affects the texture of alkaline noodles and instant fried noodles.^{532-535,551-553}

Crosbie⁵⁴³ measured the swelling power of wheat flours and starches from 13 cultivars grown in Western Australia and found that the desired texture of cooked salt noodles was correlated positively with swelling power, which agrees with the results of other researchers.^541,545 He also found a significant positive correlation between wholegrain flour swelling volume from 16 cultivars and total texture score of cooked salt noodles.⁵³⁴ Addition of 10% doubly-modified wheat starch with good swelling properties to hard wheat flour increased the cutting stress and surface firmness of cooked Oriental noodles.⁵⁴⁰ The modified granules swelled to fill many voids between gluten fibrils and yet avoided disintegration because of their resistance to the shearing action of boiling water. Wang and Seib⁵⁵⁴ found that the swelling power at 92.5°C of three top quality Australian flours was greater (20-21 g/g) than that of 12 US wheats (15-19 g/g) representing six classes.

Peak paste viscosities of flours determined with the Rapid ViscoAnalyzer were reported to correlate significantly with salt noodle eating quality.⁵⁴⁶ Konik and Moss⁵⁵⁵ found that Rapid ViscoAnalyzer peak viscosities for starches and flours from 49 wheat varieties correlated positively with salt noodle eating quality, and that setback and final viscosity at 50°C correlated negatively with eating quality. Significant negative correlation was discovered to exist between the DP 5 oligosaccharides, most likely resulting from sprout damage, and noodle eating quality.⁵⁵⁶ Furthermore, an optimum amylose content of ∼22% is required for good quality salt noodles. Using blends of natural wild type wheat flour and waxy wheat flour, Guo et al.⁵⁵⁷ confirmed that the optimal flour amylose content range for Asian salt noodles was 21-24%. Park and Baik⁵⁵⁸ described the effect of amylose content on properties of instant noodles prepared using waxy, partial waxy and regular wheat flours and reconstituted flours with starches of various amylose content. Hardness of cooked instant noodles was positively correlated with the amylose content of the starch.