Effects of long-term frozen storage on the quality and acceptance of gluten-free cassava pasta

Cold storage conditions during long-term periods can be critical for the quality of gluten-free products. The objective of this work was to elaborate gluten-free pasta using cassava starch and study the influence of different storage conditions on the textural and sensorial properties of gluten-pasta compared to regular pasta. Samples were initially frozen at two different temperatures, -50 °C and -150 °C, and then stored for six months at -25 °C. Physicochemical and rheological analyses were used to characterize the pasta dough. Then microbiological, instrumental texture, and sensorial analysis were used to further characterize the pasta throughout the cold storage period of 6 months. The gluten-free pasta's nutritional composition showed low fat and protein content and high crude fiber, carbohydrates, and energy value content in relation to the gluten-containing pasta. Both kinds of pasta dough presented a pseudoplastic behavior; however, the wheat flour pasta presented lower apparent viscosity. The texture profile of frozen pasta during the evaluation period did not significantly vary when comparing the two freezing temperatures. Although the firmness, chewability, and cohesiveness parameters slightly decreased during the storage, losses of firmness were not detected by the judges at the sensorial analysis. Finally, cassava starch pasta had a high acceptance. According to the purchase intention research, the judges routinely consume gluten-free pasta, showing the high commercialization potential of the obtained product.

Investigating the structural properties and in vitro digestion of rice flours

The physicochemical properties, swelling power, solubility, and digestibility of flour from four rice varieties (black, brown, white, and waxy rice flour) were analyzed. The results showed that the black and brown rice had high-amylose percentage (21.8% and 20.5%), a relatively low percentage of starch content (68.1% and 79.1%), and lower swelling power (6.6% and 7.6%) and solubility (13.5% and 15.7%), respectively. Waxy rice flour attributed to lower gelatinization temperatures and higher enthalpy values. Meanwhile, the brown, black, and white rice showed higher gelatinization temperature and lower enthalpy value. The black and brown rice flour exhibited lower pasting and viscosity values as compared to waxy rice flour. The results showed that all rice flour had an A-type X-ray diffraction pattern, and after cooking all rice flour showed V-type polymorphs except waxy rice flour. Brown and black rice flour after cooking have lower digestion rate than white rice and waxy rice flour, probably due to its lower expansion and solubility rates, and higher gelatinization temperature.

Morphological, physico-chemical and functional properties of underutilized starches in China

In this study, starches were isolated from different non-conventional sources (acorn, black wheat, buckwheat, coix seed, jiaoyu, kuzhu, longya lily, and naked oat) cultivated in China, and their morphological, physico-chemical, and functional properties were analyzed. Among isolated starches, significant differences (p < 0.05) were observed in morphology, pasting, crystallinity, physico-chemical, and functional properties. After a comparison with commercial corn starch, all these isolated starches presented promising and unique characteristics. The XRD profile of isolated starches presented A-type (naked oat, buckwheat, coix seed, and black wheat), B-type (longya lily, acorn and jiaoyu) and C-type (kuzhu) polymorphic structures. SEM analysis revealed that the starches isolated from different sources showed distinct shapes exclusively globular, elliptic, and polygonal shapes. The high viscosity of jiaoyu and kuzhu starch pastes can be utilized to have an advantage in instant soups and sauces. Hence, the present study will improve the scientific basis on starches from different non-conventional sources, facilitate their utilization in a variety of applications.

Impact of γ-irradiation on physicochemical characteristics, lipoxygenase activity and antioxidant properties of finger millet

In the present study, the finger millet grains were subjected to γ-irradiation at four different dosage levels: 2, 5, 10, and 15 kGy. Effect of γ-irradiation on the proximate composition, pasting properties, lipoxygenase activity, and antioxidant properties of finger millet flour was evaluated. Moisture, protein, fat, ash, and carbohydrate content of native flour was 12.96, 6.85, 2.73, 1.57, and 73.69 g/100 g, respectively. According to the results of proximate analysis, γ-irradiation significantly (p < 0.05) reduced the moisture contents and increased protein contents; however, the fat content of the irradiated flour was equal to or lower than that of the native flour. Pasting properties of the finger millet flour was reduced with the γ-irradiation. Compared with the native flour, lipoxygenase activity and malondialdehyde content decreased and radical scavenging activity, catalase, and superoxide dismutase activities increased in the irradiated flour with increasing γ-irradiation doses. Finally, the present study suggested that the γ-irradiation process improved the antioxidant enzymes and physicochemical characteristics; which could be helpful in formulating tailored made food products.

Functional and physicochemical characteristics of cookies prepared from Amorphophallus paeoniifolius flour

This study was undertaken to prepare novelly formulated cookies from elephant foot yam flour (EFYF) with refined wheat flour (RWF) and evaluate their proximate composition, quality characteristics, texture, pasting and organoleptic properties. The formulated cookies prepared from EFYF, substituting RWF up to 70% had sensory properties similar to that of refined flour cookies (control). EFYF and RWF blend revealed reduced water and oil absorption capacity with increased peak and final viscosities when compared with RWF. Reduced lightness, increased redness and hardness were observed for formulated cookies with increase in storage time. Irrespective of the decreasing trend in their texture, overall acceptance of the EFYF cookies by the consumers was increased. Sensory scores revealed the preference of consumers towards formulated cookies. Overall analysis disclosed that the cookies prepared from A. paeoniifolius flour proved acceptable not only in quality characteristics but also fulfil the demand of functional foods in preparation of cookies.