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The development of new food products obtained by extrusion processing has increased in recent years. Extrusion is used by the food industry to produce a wide variety of food products, such as ready-to-eat foods (e.g., snacks), among others. Pulses have also gained popularity as novel food ingredients in the formulation of a variety of food and food products, due to their high content of macro and micronutrients, and bioactive compounds that improve the nutritional and functional properties of the final food products. In this review, the impact of extrusion variables on proteins, carbohydrates, vitamins, phenolics and antinutritional compounds in pulses and pulse-based formulations are highlighted. Particularly, the impact of the specific mechanical energy. Also, the preservation, increase and/or reduction in those functional compounds, as a consequence of different extrusion processing conditions, are discussed.

Hypolipidemic and anti-obesity properties of extruded black, pinto and white beans were examined in male Syrian hamsters fed high fat diets for 3 weeks. The efficiency and effectiveness of extruder processing to eliminate heat-labile antinutrients were also determined. Hamsters fed a high fat diet containing 40% extruded black beans gained the same amount of weight as animals on a low-fat chow diet (based on AIN-93G). Total plasma cholesterol of the hamsters fed bean flour- based diets tended to be lower, ranging between 298 and 356 mg/dL, compared to 365 mg/dL for the control group and total and free liver cholesterol was about 50 and 33% lower, respectively, in the livers (freeze-dried) of hamsters fed the black turtle bean (BB) and pinto bean (PB) diets. The nitrogen content of the feces from hamsters fed the PB and white bean (WB) diets were 2.6x higher than the control and the excretion of deoxycholic acid (DCA) and lithocholic acid (LCA) was higher in all legume fed hamsters The results show that extrusion efficiently and economically reduces anti-nutritive factors that inhibit the digestion and absorption of proteins and carbohydrates.Graphical abstract

Baked foams made with plantain flour (PF) and sugarcane fiber (SF) were characterized by calorimetric, mechanical, physicochemical and structural techniques in order to assess the results induced by different sugarcane concentrations and fiber size on the structure of baked foams. The addition of SF to the baked samples increased their hydrophobic properties. Thermal conductivity (TC) decreased when the concentration of SF was 10 g and 7.5 g in the baked foams. The density of the biodegradable baked foams (BBFs) decreased with decreasing concentrations of SF, observing an inverse behavior in water vapor permeability (WVP) and solubility properties. The mechanical properties of the baked foams were more influenced by the concentration of SF than by the size of SF, obtained from different sieves. The scanning electron microscopy cross-sectional images of the BBFs showed that the size of SF affected the size and number of the internal cells in the BBFs., Materials science, Materials chemistry, Food science, Biodegradable baked foam, Mechanical properties, Thermal conductivity, Renewable polymers, Water vapor permeability

The aim of this study was to improve storage characteristics of brown rice by using infrared radiation drying (IRD) through comparison with hot air drying (HAD) and ambient air drying (AAD). After heating by IR from 20 °C to 60 °C within 58 s, 2.17 percentage points moisture of rough rice (initial moisture content is 25.0 ± 0.2% in dry basis) were removed without adverse effect on germination capacity of husked brown rice. Compared with AAD, IRD slowed down the increase in yellowness, water uptake and volume expansion ratio of brown rice by 47.9%, 41.0% and 37.9% after four months of storage, and decreased the temperature range and enthalpy of gelatinization, the peak and breakdown viscosities. These changes might due to the higher stabilization effect of IRD on the microstructure and thermal properties of proteins and starch granules than AAD. IRD is an effective method to improve storage stability of brown rice.

espanolEn este estudio se formularon novedosas mezclas de harina a partir de la cascara de maracuya y de arroz. Empleando un extrusor de tornillo unico, dichas mezclas se transformaron en piezas extruidas con valor agregado. Utilizando un diseno central compuesto se evaluaron los efectos de las variables propias de la extrusion —temperatura del troquel, humedad del material alimentado y contenido de la cascara de maracuya— en la expansion seccional (SEI), la expansion longitudinal (LEI), la absorcion de agua (WAI) y los indice de hidrosolubilidad (WSI) de las piezas extruidas. Se constato que las variables vinculadas con el procesamiento incidieron de manera marcada en todas las variables independientes estudiadas (SEI, LEI, WAI y WSI). Las cascaras de maracuya utilizadas en este estudio contaban con 56.76% de fibra cruda. Ademas, la imagen microestructural de las areas transversales, las estructuras internas y la apariencia superficial del material extruido con un contenido de 0-15% de la cascara de maracuya en su formulacion da cuenta de que la adicion de la cascara de maracuya produjo la disminucion de la expansion y el tamano de las celulas, aumento el grosor de la pared de las celulas de aire y les dio mayor apariencia de tener superficie aspera. El presente estudio demostro la utilidad que conlleva desarrollar materiales extruidos ricos en fibras obtenidas del arroz y de la cascara de maracuya. EnglishNovel formulations of passion fruit shell flour and rice blends were processed on a single-screw extruder, into value-added extrudates. The effects of extrusion processing variables of die temperature, feed moisture, and passion fruit shell flour content on the sectional expansion (SEI), longitudinal expansion (LEI), water absorption (WAI), and water solubility (WSI) indices of the extrudates were evaluated using a central composite design. The processing variables caused a marked effect on all the independent variables studied (SEI, LEI, WAI, and WSI). Passion fruit shell flour used in this study contained 56.76% of crude fiber. Additionally, the microstructural view of the cross-sectional areas, internal structure and surface appearance of extrudates containing 0–15% passion fruit shell flour in their formulation revealed that the addition of passion fruit shell flour led to a decrease in expansion and cell size, increase in thickness of air cell wall and rough surface appearance. This study demonstrated the usefulness of developing extruded rich in fiber from rice and passion fruit shell flour.

Pulses are well known to be gluten-free functional foods that provide a rich source of nutritional and healthy compounds with antioxidant-promoting activity. In the present study, the bioactive compounds, dietary fibre, arabinoxylans, individual phenolic compounds and tocopherols, were evaluated in different lentil flours (raw and extruded at 140 and 160 °C) formulated with nutritional yeasts, along with the changes induced by the extrusion process. The total dietary fibre and arabinoxylan content significantly (p < 0.05) increased after the extrusion process while a significant decrease of all tocopherol isoforms was also observed. Catechin, caffeic, kaempferol and quercetin derivatives were identified in the raw and extruded lentil flours. The decreases of total phenolic and individual phenolic compounds were directly related to the extrusion temperature; total phenolics and catechin hexoside exhibited a larger decrease in the lentil flours formulated with higher content of nutritional yeast (12 and 16%). The antioxidant activity results, determined using different assays, reflected the important effect of extrusion processing and food ingredients. The authors are grateful to the ALIMNOVA research group (UCM-951505/2012) and to the Foundation for Science and Technology (FCT, Portugal) and FEDER under Program PT2020 for financial support to CIMO (UID/AGR/00690/2013) and L. Barros (SFRH/BPD/107855/2015) and for the grant POCI-01- 0145-FEDER-006984 (LA LSRE-LCM), funded by FEDER, through POCI-COMPETE2020 and FCT. info:eu-repo/semantics/publishedVersion

El objetivo de esta investigación fue evaluar el efecto de la germinación sobre el contenido de compuestos fenólicos, isoflavonas y actividad antioxidante de extractos de soya obtenidos a partir de semillas germinadas por 2 y 6 días. Después de 6 días de germinación, el contenido de la mayoría de los compuestos fenólicos, incluyendo las isoflavonas, aumentó significativamente en comparación con el de las muestras de soya no germinada y la soya germinada por 2 días. Los compuestos fenólicos libres, los ácidos benzoico y vanílico, disminuyeron durante el proceso de germinación. La actividad antioxidante de la soya aumentó con el tiempo de germinación, y se observó una alta correlación entre los compuestos fenólicos totales (TPCs), la actividad antioxidante Trolox equivalente (TEAC) y el poder antioxidante reductor férrico (FRAP). Las isoflavonas también mostraron altas correlaciones con los ensayos TEAC y FRAP, y sólo la glicitina mostró correlaciones relativamente bajas. El proceso de germinación permitió aumentos en compuestos fenólicos bioactivos e isoflavona aglicona. Estos efectos mejoraron las propiedades funcionales de la soya. The objective of this research was to evaluate the effect of germination on the content of phenolic compounds, isoflavones and antioxidant activity of soybean extracts obtained from ungerminated soybeans and those germinated for 2 and 6 days. After 6 days of germination, the content of most phenolics, including isoflavones, significantly increased compared with that of samples from ungerminated soybeans and soybeans germinated for 2 days. The free phenolic compounds, benzoic and vanillic acids, decreased during the germination process. The antioxidant activity of the soybeans increased with germination time, and a high correlation was observed among total phenolic contents (TPCs), Trolox equivalent antioxidant activity (TEAC) and ferric reducing antioxidant power (FRAP). Isoflavones also showed high correlations with TEAC and FRAP assays, and only glycitin showed relatively low correlations. The process of germination allowed for increases in bioactive phenolic compounds and isoflavone aglycon. These effects enhanced the functional properties of the soybean.

Tiger nut (TN) is a nutritious source of gluten-free flour, used generally in healthy beverages, but its incorporation in gluten-free extruded snacks has not been explored. TN flour was blended at different concentrations (up to 70%) with rice flour and soluble fiber, for the development of gluten-free snacks on a twin-screw extruder. The effect of TN inclusion in the formulations was evaluated on relevant physiochemical characteristics of the snacks. Viscoamylograph of the raw formulations showed that TN addition increased (p < 0.01) onset temperature and delayed peak viscosity. In the extruded flours, TN contributed to limit the starch degradation during extrusion. Diameter, expansion ratio, true density, and total pore volume of the extrudates were reduced (pf < 0.01) by the increased TN content in the formulations, while bulk density rose. The surfaces of the extruded snacks were modified by the increasing inclusion of TN in substitution of rice in the formulations. Extrudates containing 10% TN showed the best overall texture profile. Moreover, TN addition enhanced the ash and protein content of the snacks and increased their total antioxidant activity. This study demonstrated that incorporation of 10% TN flour into rice-based formulation was suitable for making gluten-free snacks with acceptable physical properties., This research was funded by MINISTRY OF SCIENCE, INNOVATION AND UNIVERSITIES (Project RTI2018-095919-B-C21), the EUROPEAN REGIONAL DEVELOPMENT FUND (FEDER) and GENERALITAT VALENCIANA for financial support (Prometeo 2017/189). N. Gasparre thanks to GENERALITAT VALENCIANA for his predoctoral fellowship Santiago Grisolia (P/2017-104) and his mobility grant (BEFPI/2019/003).

The objective of this study was to evaluate the effects of starch source and amylose content on the expansion ratio, density, and texture of expanded extrudates, as well as to investigate the structural and molecular changes that occur in starch granules as a function of extrusion. The starches employed were rice starches (8%, 20%, and 32% amylose), carioca bean starch (35% amylose), and Hylon V® corn starch (55% amylose). The extrudates from rice starches containing 20% and 32% amylose exhibited the highest expansion ratio, while, extrudates from Hylon V® corn starch containing 55% amylose exhibited the lowest expansion ratio. The hardness values of the extrudates with 55% amylose were twice those of the extrudates with 20%, 32%, and 35% amylose. An additional finding was that although the amylopectin promoted the expansion of the gelatinized starch matrix, it failed to strengthen and sustain the walls of the extrudate bubbles during expansion.

Microbial contamination and mold growth are common causes of strawberry deterioration during storage. The growing need for extending shelf-life while enhancing the overall quality of perishable fruits has generated increasing interest in the development of novel preservation technologies. This study used electrostatic spraying (ES) technology as an innovative and efficient technique for the application of edible alginate coating enriched with carvacrol and methyl cinnamate (natural antimicrobials) on fresh strawberries. The efficiency of the electrostatic technology was compared to non-electrostatic (conventional) spray (NES) technology in terms of transfer efficiency and coating evenness. Furthermore, physicochemical and textural parameters (such as weight loss, visible decay, firmness, surface color, total soluble phenolic content, and antioxidant capacity) of ES and NES coated fruits were studied and compared to uncoated controls. ES technology demonstrated higher transfer efficiency and evenness than NES, which led to a significant reduction of visible decay over uncoated controls. The delay in microbial spoilage by ES (11 days) was greater than by NES (10 days) and uncoated strawberries (7 days). ES coating significantly inhibited strawberry decay with only 5.6 % of infected fruits, compared to 16.6 and 8.3 % for control and NES fruits after 13 days of storage, respectively. At the end of 13 days of storage, ES coating demonstrated superior performance on strawberry firmness, color retention, and weight loss reduction. Additionally, no differences were observed between uncoated and coated fruits with regard to their antioxidant and total soluble phenolics.

This study aimed to develop and characterize biodegradable films containing mucilage, chitosan and polyvinyl alcohol (PVA) in different concentrations. The films were prepared by casting on glass plates using glycerol as plasticizer. Mechanical properties, water vapor and oxygen barrier, as well as the interaction with water, were measured. The compatibility of the film-forming components and the uniformity of the films were determined by zeta potential and SEM, respectively. The glycerol and mucilage allowed obtaining more hydrophilic films. The barrier properties of the films made from 100 % chitosan were similar to composed films containing PVA up to 40 %. The results of this study suggest that the interaction between chitosan and mucilage could increase water vapor permeability. The films prepared from either 100 % chitosan or PVA showed a more hydrophobic behavior as compared to the composed films. The films were homogenous since no boundary or separation of components was observed, indicating a good compatibility of the components in the films.

Infrared radiation heating has a promising potential in improving drying rate and food safety, but its effect on the storage stability of rough rice is not known. The objective of this study was to develop an infrared drying (IRD) method to improve the storage stability of rough rice during storage. The effects of IRD on the physicochemical properties of stored rough rice were compared with those of hot air drying (HAD) and ambient air drying (AAD). Freshly harvested M206 rice was dried to a targeted moisture content of 16 % (d.b.) by using IRD, HAD, and AAD. The dried rice samples were then stored at 35.0 ± 1.0 °C and a relative humidity of 65.0 ± 3.0 % for up to 10 months. The physicochemical and cooking properties of rice samples were periodically determined over the storage duration. Compared with AAD, the yellowness index, water uptake, and volume expansion ratio of the rough rice dried with IRD and stored for 4 months were reduced by 26.3, 76.3, and 14.5 %, respectively. After 10 months of storage, the change in hardness of cooked IR-dried rice was significantly reduced by 22 % compared to that of samples dried with AAD. IRD likely caused a slight denaturation of protein and annealing of starch that was located on the surface layer of rice kernels, resulting in decreased gelatinization temperature, enthalpy, and viscosity, and reduced the changes in microstructure, but retained cooking characteristics after storage. Therefore, IRD is recommended as a promising technique that achieves high rice drying efficiency and improved storage stability.

The food industry is increasingly innovating and applying new processing technologies and ingredients to develop novel food products that meet the consumers’ demand. In this study, the effect of extrusion (at 140 °C and 160 °C) was evaluated in different lentil flours formulations enriched with nutritional yeast, in terms of α-galactosides (raffinose, stachyose, verbascose), inositol phosphates (IPs), trypsin inhibitors and lectins content. The content of α-galactosides and IPs was determined by high performance liquid chromatography. Trypsin inhibitor activity (TIA) was evaluated using a small-scale quantitative assay. The lectin content was analyzed using a haemagglutination assay and a Competitive Indirect Enzyme-linked immunosorbent assay. Extrusion promoted a significant increase, up to 85% in total α-galactosides content. After extrusion, IPs content was significantly decreased and TIA as well as lectins content had a reduction higher than 90%. Extrusion demonstrated to have a beneficial effect by increasing desirable prebiotic compounds and decreasing non-nutritional factors.

This study aims to evaluate the effects of polishing and parboiling on proximate composition, structure, phenolic compounds, antioxidant activity, cooking time and hardness of IAC-600 black rice cultivar and MPB-10 red rice lineage. Proximate analysis and light micrographs revealed higher migration of red rice proteins than black rice proteins to the endosperm as a result of parboiling. Parboiling reduced the ash content of red rice while no difference was determined in black rice. Gelatinized starch granules from both genotypes showed similar appearance. There was a decrease in relative crystallinity on both black and red rice subjected to parboiling, which was an indicative of crystallites disruption. Polishing removed more than 90% of free phenolics for both genotypes, while parboiling allowed the partial preservation of free phenolics content in polished rice. Parboiling induced an increase in the cooking time of red rice, but a decrease in the cooking time of black rice.

Extrusion process has been generally applied to the production of cereal-based snacks. However, in recent years, extrusion process has been also used for the development of pulses-based snacks, with few studies focussing on the incorporation of these food ingredients to obtain bioactive compounds enriched snacks with acceptable quality. The effects of the extrusion processing on fiber (soluble and insoluble), total available carbohydrates, tocopherols, organic acids, total phenolics, hydroxycinnamic acids, hydroxybenzoic acids and flavonols, as well as on the antioxidant capacity of different lentil-based, fiber-enriched flours were evaluated. Total dietary fiber (TDF) in the extruded flours ranged between 7.49 and 10.22 g/100 g, with a decrease from 6 to 37% which correlated with a significant increase in the fiber soluble fraction. α-, γ- and δ-Tocopherols were characterized in all the analyzed samples, being γ-tocopherol the major isoform, before and after extrusion. Additionally, a marked decrease of 83 to 94% in total tocopherol content after extrusion processing was observed and the decrease was more significant on quinic acid content. Conversely, an increase in most polyphenolic fractions was observed, probably due to the effect of extrusion process to induce hydrolysis of polyphenols bound fiber and/or proteins moieties, changing from non-extractable to extractable polyphenols. Similar increase in antioxidant activity was also observed in most formulated lentil-based flours, measured by four different antioxidant assays. Only flavonols presented an extensive content decrease of about 62 to 82%, after extrusion treatment. The authors are grateful to ALIMNOVA research group (UCM-GR35/10A) and to the CIMO research centre (Pest-OE/AGR/UI0690/2014) for financial support, and L. Barros’ research contract (“Compromisso para a Ciência 2008”).

Starch-based foams (SBFs) were prepared with corn, potato, tapioca, and chayotextle starches. A compression baking process was used to develop the SBFs. Biodegradation studies showed that different sources of starch have a particular behavior. The starches showed values of degradation of ~85%, while the degradation of SBFs was ~70%. The SBFs were conditioned at relative humidities (RHs) of 0 and 75% and temperatures of 4 and 65°C. The starch source used to prepare the SBFs did not have an effect on the mechanical properties, but the storage conditions showed a significant effect on those properties; an increase of RH causes an increase in the mechanical properties. A similar behavior was observed in the conditioned SBFs at different temperatures. The increase of the storage temperature showed a slight reduction in the values of elongation at break. Microscopy revealed that the conditions of RH and storage temperature affect the internal structure of the SBFs.

Rice is a staple food for more than half of the world's population. The parboiling process is known to increase the nutritional value of milled rice, but the process darkens the grains, with a corresponding negative effect on consumer acceptability. The aim of this study was to evaluate the effects of using different concentrations of sodium bisulfite (0, 0.2, 0.4, 0.6, 0.8, 1.0%) during the soaking step of rice parboiling process on the thiamine content and technological properties of parboiled rice. Moreover, the residual sulfite content in parboiled grains was also evaluated. The lowest concentration of 0.2% sodium bisulfite was able to significantly ( p p

The effect of extrusion operating conditions on main quality properties of glutenfree expanded snack-type products, developed from rice grits and bandinha flour formulations, was studied. The protein content in the extrudate varied from 9.44 to 14.74 g/100 g for formulations containing 13 and 47% bandinha flour, respectively, processed at 85C and 15% feed moisture. Apparent density and the radial expansion index of the extrudate were significantly (P < 0.05) affected by bean flour content, moisture content, temperature and the interaction between moisture content × temperature. The most suitable extrusion conditions were 30 g/ 100 g bean flour content, 14 g/100 g moisture content and 80C die temperature, which resulted in a product with a high radial expansion index and crude protein of 9.5 and 13 g/100 g, respectively, and a low apparent density of 0.20 g/cm 3

Maize grains are used as raw material in various food products. In countries where the production is seasonal, the grains must be stored throughout the year in order to provide sufficient maize supply for the food industries and consumers. During storage, the environmental temperature is considered as one of the most critical variables that affects grain quality. This study aimed to evaluate the effects of various storage temperatures (5, 15, 25 and 35 °C) on the proximate composition, pH, fat acidity, percentage of grains infected by molds, grain color, protein solubility and pasting properties of maize stored for 12 months. Grains stored at 35 °C during the 12 months period showed the greatest decrease in grain yellowness, pH, protein solubility and breakdown viscosity. An increase in disulfide bonds within the protein structure and interaction between starch and non-starch components seems to be responsible for the changes in protein solubility and pasting properties determined in maize during the storage period. Fat acidity and the percentage of grains infected by visible molds were concluded to be very dependent of moisture content. The result of this study demonstrated that the minimum temperature of 5 °C was able to maintain the quality of maize stored for up 12 months.

Extruded products were prepared from a corn flour and dehulled carioca bean (Phaseolus vulgaris, L.) flour blend using a single-screw extruder. A central composite rotate design was used to evaluate the effects of extrusion process variables: screw speed (318.9–392.9 rpm), feed moisture (10.9–21.0 g/100 g) and bean flour level (4.8–55.2 g/100 g) on the specific mechanical energy (SME), sectional expansion index (SEI), longitudinal expansion index (LEI), volumetric expansion index (VEI) and density (D) of the extrudates. The instrumental texture was also analyzed. The independent variables had significant effects on the physical properties (SEI, VEI and density) of extrudates, with the exception of SME and LEI. SEI increased with increasing screw speed, but a higher moisture and bean flour content resulted in decreasing SEI and VEI. The increase of moisture and bean flour increased the density of extrudates. According to texture analysis, some treatments with 30 and 45 g/100 g bean flour did not show significant differences when compared to commercial brand snacks. However, when combined with higher moisture content (≥19 g/100 g) and lower screw speed (≤333 rpm), the results of the expanded product were not satisfactory.

Recent studies have reported the health benefits of pigmented rice cultivars due to the presence of bioactive compounds in the bran layer of caryopsis. This study evaluated the proximate composition, colour, total flavonoids, anthocyanins and proanthocyanidins contents, as well as the total phenolics and antioxidant activity of IAC-600 black rice cultivar and MPB-10 red rice lineage, as a function of degree of milling (DOM), at 0%, 4%, 7%, 10%, 12% and 15% of DOM. Black rice showed a thicker bran layer than red rice. Around 80% and 65% of the ash content of red and black rice, respectively, was distributed in the bran layer. 4% DOM reduced 47% of the fat content in red rice, while in order to reduce similar fat content in black rice, a 7% DOM was necessary. The total free phenolics were around 6- and 7-fold higher than bound phenolics for black and red rice, respectively. Although the non-milled black rice presented higher free and bound phenolics contents than non-milled red rice, the red rice showed higher DPPH and ABTS+ antioxidant activities.

The purpose of this investigation was to determine the physicochemical, textural and sensorial characteristics of gluten-free spaghetti elaborated with unripe plantain, chickpea and maize flours. Luminosity (L*) of the uncooked gluten-free spaghetti was not significantly different from control sample, but in cooked spaghetti, L* value was different. The diameters of raw spaghetti (gluten-free and control) were similar, but lower diameters were determined in cooked gluten-free spaghetti; however, some composites had similar water absorption values. Gluten-free spaghetti had higher hardness, cohesiveness and chewiness than the control but had lower elasticity. The maximum peak viscosity was lower in the gluten-free spaghetti than in the control, and no breakdown viscosity was observed, although high setback viscosity was found. The overall sensorial acceptability was similar in the gluten-free spaghetti among the different formulations, but it was significantly lower than the control. It is possible to prep...

In this study, cellulose (C) and cellulose nanocrystals (CN) were blended with chayotextle starch to prepare films for the casting method. The films were stored at different temperatures and relative humidity (RH), and were analyzed by mechanical tests, X-ray diffraction, thermogravimetric analysis and biodegradation rate. The results of the mechanical characterization showed the highest values in the films with CN. In general, both type of films (with C and CN) presented an increase in the mechanical properties when the RH and temperature increased. The X-ray diffraction pattern of the films did not show any appreciable change from the effect of RH and temperature during storage. The thermogravimetric test showed that the RH and temperature of the storage did not affect the loss mass rate. The biodegradation of the films with C and CN was higher by temperature than RH, but at the longest storage times (up to 20 days) no change was observed by storage condition.

Summary The development of gluten-free spaghetti with a low amount of glycaemic carbohydrate was investigated. The goal of this study was to determine the chemical composition, cooking quality and starch digestibility of gluten-free spaghetti elaborated with mixtures of chickpea, unripe plantain and maize flours. The gluten-free spaghetti presented a higher protein, fat and ash content than the control semolina spaghetti. The solid loss among all the gluten-free spaghetti was in the range of 10.04–10.91% and not significantly different from each other. These values were almost at the limit of acceptability to be considered as good cooking quality. Total starch in the gluten-free spaghetti was lower than the control spaghetti. The lower available starch (AS) and higher resistant starch contents in the gluten-free spaghetti were associated with their lower rate of hydrolysis and predicted glycaemic index. There is a potential for developing gluten-free spaghetti with reduced amount of glycaemic carbohydrates from unconventional food ingredients such as chickpea, unripe plantain and maize flours.

Potatoes are one of the most popular carbohydrate foods in industrialized and some developing countries. However, contradicting arguments and misconceptions on potatoes as a high glycemic index (GI) food is directly affecting potato consumption during the past years. Potato varieties, maturity level, starch structure, food processing techniques and composition of the meal contribute to the GI of potatoes. Domestic boiling, baking, microwave cooking, oven cooking, extrusion and frying result in different degrees of gelatinization, and the crystallinity of starch in potato. French fried potatoes contain more resistant starch whereas boiled and mashed potatoes contribute to significant digestible starch. Extrusion processing conditions could affect the starch physicochemical structure and resulting nutritional value. Extrusion cooking makes more gelatinized starch than conventional cooking methods. Cooling or storing after processing of potatoes significantly reduces the GI due to retrogradation of starch molecules. This review provides a brief idea about the glycemic index, glycemic load, and their importance to human diseases, and detail information on the effect of food cooking methods on the glycemic index of potatoes.

Previously we have reported that extrusion significantly improved healthful potential of cereals. It was hypothesized that snacks produced by extrusion would be more healthful than their raw formulations. Bile acid binding has been reported to indicate cholesterol lowering and cancer risk reduction potential of food and fractions. Bile acid binding potential of five lentil snack raw formulations and their extruded snacks were evaluated. The raw formulations were 100% lentils (F01), 69% lentils (F02), 57% lentils + 12% supplement (F03), F03 with 125 μg/100g Chromium (F04), F03 with 536 μg/100g Chromium (F05), and their respective extruded (E) snacks E01, E02, E03, E04 and E05. The in vitro bile acid binding on an equal dry matter basis relative to cholestyramine, was F01 (0.5%), E01 (3.7%), F02 (0.6%), E02 (3.0%), F03 (1.6%), E03 (5.1%), F04 (2.0%), E04 (4.2%), F05 (0.8%) and E05 (3.6%). Replacing 12% lentils with high protein supplements (F02 vs. F03) resulted in significantly higher bile acid binding, suggesting that the supplement appears to have higher bile acid binding capacity than that of lentils. All the extruded lentil snacks had significantly higher bile acid binding compared with their raw formulations. Extruding with added chromium containing yeast resulted in significantly lower bile acid binding in a dose dependent manner. Most healthful lentil snacks were produced with the addition of high protein supplement without added chromium-containing yeast (E03). Data proved the hypothesis that lentil snacks produced by extrusion are significantly more healthful than their raw formulations.

The objective of this work was to study the effect of enzymatic hydrolysis of black bean protein concentrate using different enzymes. Bean proteins were extracted and hydrolyzed over a period of 120 min using the enzymes pepsin or alcalase. The protein hydrolysates’ molecular weight was assayed by electrophoresis and the antioxidant activity was evaluated by the capturing methods of free radicals ABTS●+ and DPPH. Electrophoretic results showed that the bands above 50 kDa disappeared, when the beans protein was subjected to hydrolysis with pepsin. The bean protein hydrolysate obtained by hydrolysis with alcalase enzyme, showed higher antioxidant activity for inhibition of the radical ABTS●+. However, the hydrolysates obtained by hydrolysis with pepsin had higher antioxidant activity for inhibition of the radical DPPH. The use of pepsin and alcalase enzymes, under the same reaction time, produced black bean protein hydrolysates with different molecular weight profiles and superior antioxidant activity than the native bean protein.

Extruded/injection-molded composites of excellent mechanical property were produced from plantain flour (PF) blended with ethylene–vinyl alcohol (EVA) and glycerol. Scanning electron microscopy (SEM) revealed that composites had a smooth surface, indicative of an excellent compatibility between PF, EVA, and glycerol. Generally, tensile strength (TS), elongation at break (%E), and the displacement (DM), all decreased with increased PF content in the composite accompanied by an increase in Young's modulus (M). The composites with higher PF contents (60% or higher) had more stable mechanical properties. Selected composites (60% PF content) stored at −20°C and 4°C for 40 h showed only minor changes in mechanical properties compared with controls (23°C). However, samples stored for a similar period at 80°C were drastically altered in their mechanical properties resulting in huge increases in TS and M and a 10-fold decrease in the %E. Samples prestored at various relative humidities (RHs) for 40 h exhibited only slight decrease in TS and M and a concomitant increase in the %E with increased RH. Interestingly, sample prestored at both −20°C and 80°C exhibited significantly higher rates and extents of degradation. SEM analysis of samples left in compost for 8 weeks showed a rapid surface erosion and material deterioration with time. Evaluation of the color produced during heat processing of starch in PF as a result of Maillard reaction showed an increase in the values of luminosity (L*), chroma (C*), and hue angle (h*) with decreased PF content in the composite. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Foods with antioxidant capacity provide protection against cardio-vascular, certain forms of cancers, and Alzheimer's diseases caused by oxidative damages and contribute health benefits. The effect of extrusion cooking on the antioxidant capacity and color attributes of extruded products prepared from 3 selected formulations of purple potato and yellow pea flours using a co-rotating twin screw extruder were studied. Expansion ratios of the extruded products varied from 3.93 to 4.75. The total antioxidant capacities (TAC) of the extruded products, using DPPH assay, were 3769 to 4116 μg trolox equivalent/g dry weight sample and not significantly different (P > 0.05) from their respective raw formulations. The total phenolic contents (TP) of the extruded products varied from 2088 to 3766 μg of gallic acid equivalent/g dry weight sample and retained 73% to 83% of the TP from the raw formulations after extrusion. The total anthocyanins contents (TA) in the extrudates were 0.116 to 0.228 mg of malvidin-3-glucosides/g dry weight sample. Compared with their raw formulations, significant losses (60% to 70%) of the TA in the extruded products occurred due to extrusion cooking. Browning indices and color attributes such as brightness, chroma, and hue angle agreed with degradation of anthocyanins in the extruded products. However, extrusion cooking retained antioxidant capacities of the raw formulations in the extruded products either in their natural forms or degraded products with radical scavenging activity. This study demonstrated the potential for the production of puffed extruded food products with the improved antioxidant content from colored potatoes and pulse formulations.

Measuring antioxidant activity using a biologically relevant assay adds important evidence to aid in understanding the role of phytochemicals based on data from in vivo and chemical assays of extrusion processed purple potato and pea flours. A cellular antioxidant activity assay could provide biologically relevant information on bioactive compounds in raw as well as processed food products. The objective of this study was to investigate the complete phytochemical profiles, antioxidant activity, cellular antioxidant activity, and their contribution to bioactivity in purple potato flour, dry pea flour, raw formulations, and extrusion cooked products prepared with the above ingredients. The free fraction of extracts contributed 68, 64, and 88% to total phenolics, total antioxidant activity (ORAC value), and total flavonoids, respectively, in purple potato flour (PPF). Similarly, extracts in the free fraction contributed 87, 86, and 64% to total phenolics, total antioxidant activity (ORAC value), and total flavonoids, respectively, in dry pea flour (DPF). The amount of total phenolics and total flavonoids in purple potato flour and the antioxidant activity of PPF and DPF were comparable to published data. However, a higher amount in the total flavonoids and lower in the total phenolics of DPF were observed. Caffeic, p-coumaric, and ferulic acids were mostly observed in the bound extracts of raw formulations as in the extrudates, whereas chlorogenic acid was predominant in the free extracts. The extruded products had significantly higher (p < 0.05) content of total phenolics, ORAC antioxidant activity, and flavonoids, compared to the raw formulations. Extrusion processing increased the cellular antioxidant activity of the extrudates prepared from 35:65 and 50:50 PPF/DPF (w/w) of ingredients compared with control raw formulations in a dose-dependent manner. Increase of PPF significantly increased (p < 0.05) the cellular antioxidant activity of 35-50% PPF formulations.

Colored potatoes (Solanum tuberosum L.) are a significant source of antioxidants frompolyphenols,carotenoidsandascorbicacid.Inthisstudy,theretentionof total antioxidants in fresh colored potatoes and processed potato flakes prepared as potential ingredients for snack foods was studied. Total antioxidant capacity, total phenolics and total anthocyanins were higher in purple potato flesh compared with those from red, yellow and white potato cultivars. Peeled purple potatoes were blanched and dehydrated by freeze drying (FD), drum drying and refractance window drying to prepare potatoflakes. Resultsshowed no significant losses in total antioxidant capacity and total phenolic content in flakes in all drying methods obtainedunderstudy.However,45,41and23%lossesintotalanthocyaninscontent were observed in potatoflakes after FD,drum drying and refractive window drying, respectively.Colored potatoes could provide an excellent source of antioxidant-rich ingredient for the production of nutritionally enhanced food products.

This research studied developing quick cooking brown rice by investigating the effect of ultrasonic treatment at different temperatures on cooking time and quality. The medium grain brown rice was ultrasonically treated in water at temperatures of 25, 40, and 55°C for 30 min and then dried by air at 25°C to its initial moisture content (11.0 ± 0.6%, wb) before cooking. The microstructure of rice kernel surface, chemical composition, and optimal cooking time of treated brown rice were determined. The pasting and thermal properties and chemical structure of flour and starch from treated brown rice were also examined. The results showed that the optimal cooking times were 37, 35, and 33 min after treatment at 25, 40, and 55°C, respectively, compared to the control of 39.6 min. The ultrasonic treatment resulted in a loss in natural morphology of rice bran, allowing water to be absorbed by a rice kernel easily, particularly at high-temperature treatment. Even through rice flour still maintained an A-p...

The objective of this study was to evaluate the effects of starch source and amylose content on the expansion ratio, density, and texture of expanded extrudates, as well as to investigate the structural and molecular changes that occur in starch granules as a function of extrusion. The starches employed were rice starches (8%, 20%, and 32% amylose), carioca bean starch (35% amylose), and Hylon V

abuticaba (Myrciaria cauliflora. Mart) is a highly perishable fruit native to Brazil, which is consumed both fresh and industrially processed in the form of juices, jams, wines and distilled liqueurs. This processing generates a large amount of waste by-products, which represent approximately 50% of the fruit weight. The by-products are of interest for obtaining valuable bioactive compounds that could be used as nutraceuticals or functional ingredients. In this study, fermented and non-fermented jabuticaba pomaces were studied regarding their hydrophilic and lipophilic compounds, as well as their antioxidant properties, including: soluble sugars, organic acids and tocopherols (using high performance liquid chromatography coupled to refraction index, diode array and fluorescence detector, respectively); phenolics and anthocyanins, (using liquid chromatography coupled to diode array detection, and mass spectrometry with electrospray ionization); and fatty acids (using gas-liquid chromatography with flame ionization detection). The analytical data demonstrated that jabuticaba pomaces are a rich source of bioactive compounds such as tocopherols, polyunsaturated fatty acids and phenolic compounds (namely hydrolyzable tannins and anthocyanins) with antioxidant potential. Therefore, jabuticaba pomace may have good potential as a functional ingredient in the fabrication of human foods and animal feed. The authors are grateful to the Foundation for Science and Technology (Portugal) for financial support to CIMO (strategic project Pest-OE/AGR/UI0690/2011) and to L. Barros (researcher contract under “Programa Compromisso com Ciência-2008”).

A heat expansion process similar to that used for expanded bead polystyrene was used to expand starch-based compositions. Foam beads made by solvent extraction had the appearance of polystyrene beads but did not expand when heated due to an open-cell structure. Nonporous beads, pellets, or particles were made by extrusion or by drying and milling cooked starch slurries. The samples expanded into a low-density foam by heating 190-210 degrees C for more than 20 s at ambient pressures. Formulations containing starch (50-85%), sorbitol (5-15%), glycerol (4-12%), ethylene vinyl alcohol (EVAL, 5-15%), and water (10-20%) were studied. The bulk density was negatively correlated to sorbitol, glycerol, and water content. Increasing the EVAL content increased the bulk density, especially at concentrations higher than 15%. Poly(vinyl alcohol) (PVAL) increased the bulk density more than EVAL. The bulk density was lowest in samples made of wheat and potato starch as compared to corn starch. The expansion temperature for the starch pellets decreased more than 20 degrees C as the moisture content was increased from 10 to 25%. The addition of EVAL in the formulations decreased the equilibrium moisture content of the foam and reduced the water absorption during a 1 h soaking period.

Scanning electron microscopy (SEM) was used to study and compare the structural characteristics of black beans after 2 years of storage under ambient conditions (AC) and refrigerated hypobaric conditions (RHC). The exterior surface of the seed coats of the black beans were covered with small flake-like materials randomly clustered together. The hilar regions of black beans stored under either AC or RHC were similar, and the “linea lucida” exhibited well defined double palisade cell layers in both bean treatments. Cross sections of the seed coats revealed that the parenchymal cell layers of the beans stored under AC were disrupted and frequently exhibited large intercellular spaces between the cell layers. The parenchymal cell layers of the beans stored under RHC demonstrated little disruption of the cell layers, with only occasional intercellular spaces between the cell layers. Cotyledon cross sections of blackbeans showed that the cotyledon cells of the beans stored under RHC exhibited many large intercellular spaces characteristic of normal beans. Conversely, cotyledon cross sections of the beans stored under AC exhibited cotyledon cells with few small intercellular spaces characteristic of hard-to-cook beans.

Seed microstructure provides complementary information to physicochemical determinations. Scanning electron micrographs of cross sections of black bean extrudates illustrated the increase in volume expansion, with an increase of sodium bicarbonate (NaHCO3) in the extrudate. This increase in volume expansion is attributed to the increase in air cell size and corresponding decrease in air cell wall thickness with additional concentrations of NaHCO3. The measured increase in diameter and expansion ratio of extrudates with NaHCO3 addition may be explained by the increase in number of air cells within the extrudate and the increase in pores in the gelatinized starch matrix of air cell walls. Extrusion conditions, which involved the use of heat and moisture, provided the necessary conditions for the release of CO2 from NaHCO3 during processing. Expansion ratio increases between the control extrudate, and extrudate with 0.5% NaHCO3 addition were twofold at the node and 1.8-fold at the area between the nodes. Statistical analysis of color data exhibited no significant change in L*, hue or chroma across concentrations of NaHCO3 for nonextruded flours. A simple linear regression adequately described changes in L* and hue for extruded flours. However, a curvilinear relationship was needed to explain changes in chroma versus NaHCO3 for extruded flours, making changes in chroma measurements less easy to interpret. The color data in this study serve as primary information for future establishment of cut-off values of color for the development of an acceptable legume snack.

Extrusion cooking and chemical leavening agents such as sodium bicarbonate (NaHCO3), may induce changes in carbohydrate fractions of extruded black bean (Phaseolus vulgaris L.) flours. Bean flours at 20% moisture, with NaHCO3 added at levels from 0.0 to 2.0%, were extruded at a screw speed of 200 rpm. The temperature profile ranged from 23 to 160C. Extruded bean flours with 0.1 to 0.4% added NaHCO3 were selected for sugar analyses based on color and flavor acceptability. The major sugars determined in the bean samples were galactose (0.10%), sucrose (2.08%), and stachyose (2.00%). Extruded samples had an increase in total sugars. Also, an increase in soluble fiber and a decrease of insoluble fiber fractions were observed. Sucrose was the only free sugar which concentration decreased consistently as a result of extrusion processing. Extrusion conditions and the selected levels of NaHCO3 used in this study did not significantly change the oligosaccharide content of the black bean flours.

A central composite design using RMS (Response Surface Methodology) successfully described the effect of independent variables (feed moisture, die temperature and soybean proportion) on the specific parameters of product quality as expansion index (EI), water absorption index (WAI), water solubility index (WSI) and total color difference (ΔE) studied. The regression model indicated that EI, WAI, WSI and ΔE were significant (p 0.05) with coefficients of determination (R(2)) of 0.7371, 0.7588, 0.7622, 0.8150, respectively. The optimized processing conditions were obtained with 25.8 % feed moisture, 160 °C die temperature and 58 %/42 % soybean/corn proportion. It was not found statistically changes in amino acid profile due to extrusion process. The electrophoretic profile of extruded soybean/corn mix presented low intensity molecular weight bands, compared to the unprocessed sample. The generation of low molecular weight polypeptides was associated to an increased in In vitro protein digestibility (IVPD) of the extrudate. The FTIR spectra of the soybean/corn mix before and after extrusion showed that the α-helix structure remained unchanged after extrusion. However, the band associated with β-sheet structure showed to be split into two bands at 1624 and 1640 cm(-1) . The changes in the β-sheet structures may be also associated to the increased in IVPD in the extruded sample.

Selected physical and chemical characteristics were studied on black beans ( Phaseolus vulgaris L.) after 2 years of storage under refrigerated hypobaric conditions (RHC) and ambient conditions (AC). Black beans stored under RHC of 4.5°C, 50–60% relative humidity and atmospheric pressure of 125 mm Hg exhibited quality factors characteristic of fresh beans, such as shorter cooking time, smaller quantities of solids loss, electrolytes leached, and percentage of hardshell than beans stored at AC of 23–25°C and 30–50% relative humidity. Additionally, beans stored under RHC demonstrated greater germination rate (93%) than beans stored at AC (72%). Beans stored at AC exhibited quality factors characteristic of hard-to-cook (HTC) beans. Percentage water absorption indicated a faster initial hydration rate in beans stored under RHC compared to beans stored at AC until after 12 h of soaking, when both reached a similar hydration rate. Moisture content of beans stored under RHC was similar to that of beans prior to storage, while the moisture content of beans stored at AC was significantly lower. Crude protein, crude fat, and ash concentration of beans prior to storage and beans stored for 2 years under RHC or AC were not significantly different. The electrophoretic profile of the main protein of beans, globulin G1, was not altered by the storage conditions. The combined effect of refrigeration and hypobaric storage conditions demonstrated potential for maintaining the fresh quality of beans in storage for up to 2 years.

The effects of composition, temperature, and storage time on the textural attributes of a starch–sucrose gel system were determined by means of textural profile analysis (TPA) tests. Mixtures of high amylose corn starch, sucrose, and water were jet cooked at temperatures of 110–150 °C, rapidly cooled to gels on a refrigerated belt, and stored at 1 °C. Treatment temperature, storage time, sucrose/starch ratio and water added/solids ratio were used as independent variables. The ranges of sucrose, starch, and water added were 0–14.9, 14.4–33.6, and 48.3–77.8 g/kg, respectively. All four independent variables were found to be significant in second order response surface equations, describing all textural attributes but adhesiveness. Hardness, fracturability, gumminess, and chewiness were exponentially related to quadratic functions of the variables while resilience, cohesiveness, and springiness were linearly related. Adhesiveness values were low and independent of the variables. In general, values of textural attributes increased with temperature and storage time, and were inversely related to sucrose/starch ratio and water added/solids ratio.

A series of unsaturated branched esters were purified by preparative gas chromatography and their odor thresholds were determined using sensory panel methods. In general, unsaturated branched esters had higher odor thresholds than their saturated counterparts. Double bond position and configuration had marked influences on the odor threshold. In most cases, the addition of a double bond in the C-2 position of the acid resulted in significantly higher odor thresholds while the addition of a double bond in positions further away from the acid carbonyl had a smaller effect on the odor threshold. Ethyl 2-methyl-4-pentenoate had the lowest odor threshold (0.01 μL/10 3 L) of the esters tested while methyl (E)-2-methyl-2-butenoate (methyl tiglate; 130 μL/10 3 L) had the highest odor threshold.