**3.1.4 Antioxidant activity**

44 Thermoplastic Elastomers

Abu-Hardan et al. (2011) investigated the addition of three commercial vegetable oils (1 to 8%) to extruded wheat starch, namely: palm oil, soybean oil and sunflower oil. The effects of the addition of the oils on the sectional expansion of extrudates was complex in which a significant increase up to a 5% oil concentration was reached and further increase of oil quantities resulted in a drastic reduction and no significant differences between oils were noticed. However, the crystallinity indexes indicated no interference from the three oils in the complex formation. These authors suggested that the endogenous lipids naturally

Limón-Valenzuela et al. (2010) obtained a functional third-generation snack food with good expansion characteristics using a microwave oven, and this snack has health benefits due to the addition of milk protein concentrate ( 0-10%) and quality protein maize ( 20%) in a blend of corn starch (80%). These authors used a laboratory single-extruder with a 3:1 compression ratio, feed moisture (20-30%), a rectangular die, and a central composite non-routable model

According to the increased demand for new healthy snacks as an alternative for fried starchbased snacks with low nutrient density, Cho & Rizvi (2010) showed the potential of supercritical fluid extrusion (SCFX) technology for healthy snack food production containing high whey protein concentration. SCFX chips had uniform cellular

Lobato et al. (2011) developed a functional puffed product for extrusion containing 250 g/kg corn starch, 375 g/kg soy flour, and 375 g/kg oat bran extruded under the process conditions of 250 g/kg moisture; 45 g/kg inulin and 130ºC). The puffed product had 212.6 g/kg fiber, 281.0 g/kg protein, and a caloric value of 319.1 kcal/100 g and it was well

Céspedes et al. (2010) obtained extruded orange pulp using a Brabender laboratory singlescrew extruder (20:1 Céspedes 2010) and observed that it could also be added to high-fiber foods as a low-calorie bulk ingredient to reduce the calorie level, since it showed potential

Souza & Lionel (2010) verified that the mixture of cassava starch and dried orange pulp extruded under different conditions (0 to 20% of fibers in the mixture), (14.6 to 21.4% moisture), and (60.8 to 129°C temperature of extrusion), could aim at the use in high-fiber

Bello-Pérez et al. (2006) extruded starches isolated from unripe banana (*Manguifera indica* L.) and mango (*Musa paradisiaca* L.) fruits to obtain a product with high content of resistant starch (RS) and verified that RS formation in the extruder for banana starch was affected positively by temperature and inversely by moisture. Moisture did not significantly affect

microstructure that cannot be obtained using conventional steam-based extrusion.

accepted by the panelists in the sensory evaluation, mainly in terms of texture.

present in wheat starch were sufficient to complex the starch.

**3.1.1 Oils** 

**3.1.2 Protein** 

with two variables

**3.1.3 Fibers and resistant starch** 

hypoglycemic effects.

instant products.

RS formation in mango starch.

The blends of various formulations of durum wheat flour (8-20%), partially defatted hazelnut flour (PDHF) (5-15%), fruit waste blend (3-7%) and rice grits were extruded using single-screw extruder and when higher, PDHF and fruit waste content caused an increase in the total phenolic content and antioxidant activity of the extruded samples, whereas percentage starch gelatinization and digestibility values decreased (Yaĝci & Göĝůş, 2009).

Limsangouan et al. (2010) demonstrated the effect of extrusion processing on the functional properties of extruded snack foods developed from cereal and legumes, and the by-products from herbs and vegetables, and the extrusion process slightly decreased the antioxidant capacity and phenolic content.

Table 2 shows new starches that are been used in thermoplastic extrusion researches.
