Rheological Approaches of Wheat Flour Dough Enriched with Germinated Soybean and Lentil

Germination is a convenient technique that could be used to enhance the nutritional profile of legumes. Furthermore, consumers’ increasing demand for diversification of bakery products represents an opportunity to use such germinated flours in wheat-based products. Thus, this study aimed to underline the effects of soybean germinated flour (SGF) and lentil germinated flour (LGF) on the rheological behavior of dough during different processing stages and to optimize the addition level. For this purpose, flour falling number, dough properties during mixing, extension, fermentation, and dynamic rheological characteristics were evaluated. Response surface methodology (RSM) was used for the optimization of SGF and LGF addition levels in wheat flour, optimal and control samples microstructures being also investigated through epifluorescence light microscopy (EFLM). The results revealed that increased SGF and LGF addition levels led to curve configuration ratio, visco-elastic moduli, and maximum gelatinization temperature rises, while the falling number, water absorption, dough extensibility, and baking strength decreased. The interaction between SGF and LGF significantly influenced (p < 0.05) the falling number, dough consistency after 450 s, baking strength, curve configuration ratio, viscous modulus, and maximum gelatinization temperature. The optimal sample was found to contain 5.60% SGF and 3.62% LGF added in wheat flour, with a significantly lower falling number, water absorption, tolerance to kneading, dough consistency, extensibility, and initial gelatinization temperature being observed, while dough tenacity, the maximum height of gaseous production, total CO2 volume production, the volume of the gas retained in the dough at the end of the test, visco-elastic moduli and maximum gelatinization temperatures were higher compared to the control. These results underlined the effects of SGF and LGF on wheat dough rheological properties and could be helpful for novel bakery products development.

Effect of Acetylation, Hydroxypropylation and Dual Acetylation-Hydroxypropylation on Physicochemical and Digestive Properties of Rice Starches with Different Amylose Content

Four rice (Oryza sativa L.) starches widely differing in amylose content were subjected to acetylation, hydroxypropylation, and dual modification involving acetylation followed by hydroxypropylation. The starches showed a higher affinity to hydroxypropyl substitution. However, acetylation caused a significant alteration in the glycosidic matrices. The changes in physicochemical properties were most prominent in the dual-modified samples. Hydroxypropylated and dual-modified granules showed greater swelling power with structural retention. Degrees of acetylation were high in the amorphous regions of waxy and low amylose starches (0.04 and 0.05). Minor granular swelling was observed under SEM. Substitution partially dissociated side-chain superhelices, lowering crystallinity values by 3.12-4.58%, however retaining the native A-type XRD patterns. Glycosidic dissociation and enhanced hydrophilicity caused a significant lowering of gelatinization temperature (To, Tp, Tc), enthalpy (H), and cooking time as observed from DSC and RVA results. Low setback viscosity and low syneresis during freeze-thaw cycles indicated the decreased tendency of modified starch chains to realign. Dual modified starches could be cooked to thinner and more precise pastes, which are highly resilient to retrogradation. Significant increases in enzyme-resistant RS and SDS (up to 20% of each) were recorded. The dual modification method could suitably alter the properties of starches for food use.

Biofilms Production from Avocado Waste

Objective: To obtain biofilms from starch and cellulose present in the avocado (Persea americana) peel and seed. Materials and methods: The starch characterization included humidity, gelatinization temperature, paste clarity, absorption index, solubility index, swelling power, amylose, amylopectin, amount, and starch yield. Five mixtures were made with 3 g of starch, 5 mL of 30 % NaOH (w/v), 3 g of cellulose, and different proportions for glycerin: 2 g; 2.5 g; 3 g; 3.5 g; 4 g, and PVA: 2 g, 3 g, 4 g, 5 g, and 6 g. Films were formed on acrylic plates, using the casting method. The bioplastic was characterized in terms of moisture, solubility in water, density, thickness, biodegradability, stress, deformation, and modulus of elasticity. Results and discusión: The addition of cellulose to the mixture does not contribute to film formation, unlike PVA which did. The film had the best physical appearance with a mixture of 2 g of glycerin and 6 g of PVA. The bioplastic characterization was 23.43 % humidity, 39.39 % for water solubility, 1.52 g/cm3 density, 0.58 mm thickness, 21.03 % weight loss for the biodegradability test, 1.53 MPa for tension, 21.25 % deformation, and 10,04 MPa for the modulus of elasticity. Conclusions: The bioplastic obtained did not show the resistance of traditional plastic. However, the results obtained serve as a starting point for the realization of other formulations, aimed at producing a bioplastic capable of competing with its synthetic relatives.

Thermal and functional properties of starch extracted from tubers cultivated in the Ecuadorian Andean region

Thermal and functional properties of starch extracted from American taro and Indian shot were determined to assess their use in food products. Starch was extracted by the wet-milling method. Physicochemical composition was determined following the Association of Official Agricultural Chemists (AOAC) protocols. Total fibre was measured by the Total Dietary Fiber Assay Kit. The morphology of starch granules was observed by scanning electronic microscopy (SEM). Gelatinization temperature and viscosity were measured by Differential Scanning Calorimetry (DSC) and with a rapid viscosity analyser (RVA), respectively. Swelling capacity, solubility index, and absorption index were measured at 15, 60, 70, 80, and 90 °C. The yield for Indian shot (72.5 %) was higher of that for taro (60.2 %). No significant differences (p &gt; 0.05) were found for moisture, ashes, total fibres, and protein; significant differences were found for fat content, total carbohydrates, amylose, and amylopectin. Granules of Indian shot starch featured ovoid shapes (diameter, 30 µm), while granules of American taro starch presented round shapes (diameter, 15 µm. Gelatinization temperature for American taro (78.33 °C) was higher of that for Indian shot (65.28 °C). Maximum viscosity in Indian shot (3,535.5 cP) was higher of that in American taro (2,446.5 cP). Concerning functional properties, Indian shot starch yielded higher values. Moreover, at high temperature values, American taro starch presented better gelling results than those in Indian shot.

Karakteristik Komposit Bioplastik dalam Variasi Rasio Pati Gadung (Dioscorea hispida D.) - Glukomanan dan Suhu Gelatinisasinya

This study aims to determine the effect of variations in the ratio of gadung starch (Dioscorea hipida D.) - glucomannan and their interaction on the characteristics of bioplastic composites and to determine the ratio of gadung starch (Dioscorea hipida D.) - glucomannan and its gelatinization temperature which gives the best characteristics of bioplastic composites. This study used a factorial randomized block design (RBD) with two factors. The first factor is the variation in the ratio of the gadung tuber starch - glucomannan which consists of 3 levels, namely (60:40), (50:50), (40:60). The second factor is the gelatinization temperature which consists of 3 levels, namely 75 ± 1oC, 80 ± 1oC 85 ± 1oC. Each treatment was grouped into 2 based on the time of the manufacturing process so that 18 experimental units were obtained. The variables observed were tensile strength, elongation at break, elasticity, and biodegradation time. The data obtained were analyzed of variant and continued with the HSD Tukey. The results showed that the ratio of gadung - glucomannan starch, gelatinization temperature, and their interactions had a very significant effect on tensile strength, elongation at break, and elasticity but it did not significantly affect the biodegradation time. The ratio of gadung tuber starch - glucomannan (60:40) with a gelatinization temperature of 85 ± 1oC produced the best bioplastic characteristics with a tensile strength value of 4.4 MPa, an elongation at break of 9.5%, and elasticity value of 22.390 MPa and resulted in a degradation time of 7 days. 2 variables meet the standards, namely: the extension when the bioplastic composites have broken up has met the SNI plastic standards and biodegradation has met the international plastic standard ASTM 5336. Keywords: bioplastic, composite, gadung starch, gelatinization temperature, glucomannan,

Quality Evaluation of Custard Produced from Blends of Sweet Potato and Corn Starch Enriched with Defatted Soybean

Custard is a thick, rich, creamy sweet or savory dessert, made mixtures of eggs or egg yolks, milk or cream and commonly consumed in most part of Africa especially Nigeria. This research was carried out to determine the physicochemical properties and sensory characteristics of custard produced from the blends of sweet potato and corn starch enriched with defatted soybean flour. The sweet potato was peeled, washed and diced into small cubes to aid milling while the maize grains were cleaned and soaked in water for 24 hours, and they were separately milled and filtered. The filtrates were allowed to settle for four hours, the starches were obtained and dried at 70°C and 60°C for 8 hours and 5 hours respectively. The soybean was cleaned, soaked, boiled, toasted, dehulled, milled and defatted in petroleum ether. Ten custard samples were then formulated using sweet potato starch, corn starch and defatted soybean flour respectively in the following ratios: 100:0:0; 80:10:10; 70:20:10; 60:30:10; 50:40:10; 40:50:10; 30:60:10; 20:70:10; 10:80:10; 0:100:0. The custard formulations were evaluated for their physicochemical and sensory characteristics, using commercial custard (Checkers custard) as control. The result of the proximate composition showed that moisture, ash, crude fibre, crude protein and carbohydrate content in % ranged from 5.40-18.08, 0.70-3.07, 1.16-6.52, 0.82-5.23, 1.31-9.91 and 68.87-85.25, respectively. The functional properties also showed that least gelation concentration (%), bulk density (g/cm), swelling power and gelatinization temperature (oC) ranged from 4.00-10.00; 0.59-0.83; 6.37-8.02 and 69.2-80.1, respectively. The result showed that the swelling power differed significantly (p<0.05) from each other and some of the samples differed significantly in bulk density, least gelation and gelatinization temperature, respectively. Sensory evaluation carried out on different samples of the custard formulation showed that the control sample (Checkers custard) had the highest score of overall acceptability. The 100% corn starch and 100% sweet potato starch were accepted by the consumers as an alternative to the commercial custard product. The enrichment of custard with soybean contributed to an increase in the nutritional value of the custard.

Efficacy of Irrigation Interval after Anthesis on Grain Quality, Alkali Digestion, and Gel Consistency of Rice

The management of amylose and protein contents and cooking quality are the main challenges in rice macronutrients and quality improvement. This experiment was conducted to examine the rice grain quality, alkali digestion, and gel consistency responses to irrigation interval after anthesis. Three rice varieties (K1, K3, and K4) were subjected to different irrigation intervals (1, 2, and 3 d) after anthesis. The findings of this study showed that the protein content was markedly increased from 6.53–6.63% to 9.93–10.16%, whilst the amylose content was decreased significantly from 22.00–22.43% to 16.33–17.56% under stressed treatments at irrigation intervals, whilst the quantity of fatty acids was not affected. The 3-d irrigation interval recorded the highest protein content but the lowest amylose value. In addition, this treatment shows lower gelatinization temperature, but it is negatively associated with hard gel consistency under irrigation interval. This study highlights that the water management following a 3-d irrigation interval from anthesis is a useful and simple treatment to improve rice nutrients and grain cooking quality.