Effect of extrusion cooking on the physicochemical properties, resistant starch, phenolic content and antioxidant capacities of green banana flour

Mechanisms of starchy foods glycemic index reduction under different means and their impacts on food sensory qualities: A review

Diabetes has become a significant global health issue, driving the adoption of low glycemic index (GI) diets and positioning low-GI foods as a key research focus. Although methods for lowering the GI of foods have been reviewed, a comprehensive analysis of the underlying mechanisms is lacking. Moreover, GI-lowering techniques, whether through exogenous additives or specific processing methods, can influence food sensory qualities and impact storage stability. However, systematic reviews on these effects are limited. This review summarizes mechanisms for reducing the GI of starchy foods, focusing on four key strategies: inhibiting digestive enzymes, altering substrate structure, blocking enzyme-substrate interactions, and stimulating insulin secretion. It also addresses the sensory impacts of these GI-reduction methods. Additionally, the review evaluates how certain nutrient additions affect food stability during storage, aiming to offer scientific guidance for the development of low-GI starchy foods.

Andean Pseudocereal Flakes with Added Pea Protein Isolate and Banana Flour: Evaluation of Physical-Chemical, Microstructural, and Sensory Properties

In order to obtain a highly nutritious extrudate, a combination of pseudocereals, vegetable protein, and banana flour, a fruit with high sensory acceptability, was used. The objective of the research was to produce a multi-component extrudate (ME) based on cañihua and quinoa with the addition of pea protein isolate and banana flour. The response variables evaluated were composition, expansion, hydration, colour, and hardness properties, as well as the microscopy and sensory characteristics of the flakes produced. These flakes were compared with three commercial extrudates, commercial quinoa-based extrudate (QE), commercial corn-based extrudate (CE), and commercial wheat-based extrudate (WE), which had similar characteristics. The ME showed a higher protein content compared to commercial extrudates (13.60%), and it had significant amounts of lipids, fibre, and ash. The expansion of the ME was like commercial quinoa but significantly lower than the CE and the WE in terms of expansion (p < 0.05). Regarding the absorption and solubility indices of the ME, these indicated that it had lower starch fragmentation compared to the commercial CE and WE. In addition, the instrumental hardness of the ME was higher than the commercial ones due to the complex nature of the product. Through scanning electron microscopy (SEM), it was observed that the ME showed some remaining extrusion-resistant starch granules from quinoa and cañihua with the presence of protein bodies. Finally, the flash profile described the ME as having a pronounced flavour, higher hardness, and lower sweetness, and the free sorting task allowed it to be differentiated from commercial extrudates based on its natural appearance and chocolate flavour.

Research Progress on the Physicochemical Properties of Starch-Based Foods by Extrusion Processing

Extrusion is a crucial food processing technique that involves mixing, heating, shearing, molding, and other operations to modify the structures and properties of food components. As the primary energy source material, the extrusion process induces significant physical and chemical changes in starch that impact the quality of final products. This review paper discusses novel technologies for starch extrusion and their influence on the physical and chemical properties of starch-based foods, such as gelatinization and retrogradation properties, structural characteristics, and digestion properties. Additionally, it examines the application of extrusion in starch processing and the interactions between starch and other food components during extrusion. This information sheds light on the structural and property alterations that occur during the extrusion process to create high-quality starch-based foods.

The role of non-starch constituents in the extrusion processing of slow-digesting starch diets: A review

Starch is the main source of energy for the human body through diet, and its digestive properties are closely related to the occurrence of chronic diseases. Extrusion technology, which is characterized by low cost and high efficiency, has been widely used in the field of reducing starch digestibility and modifying starch, and it has great potential for designing and manufacturing precision nutrition for specific populations. However, this aspect of study has not been systemically summarized, so we systematically discuss the role of extrusion and non-starch components in starch modification in this review. This review focuses on the following sections: the effect mechanisms of extrusion on starch digestibility in terms of granule morphology, crystal structure, viscosity and pasting characteristics; the different effects of single or multiple non-starch components on starch digestibility under extrusion; and some of the current applications of extrusion technology in the development of slow-digesting starchy diets. This review summarises the effects of extrusion techniques and non-starch components on starch digestibility under extrusion conditions, and provides the appropriate theoretical basis for the application of starch-based foods in the development of slow-digesting diets, the precise nutritional design of specific populations, and the improvement of the structure of healthy human diets.

Enzymatic hydrolysis method for development of low glycemic index rice flour from temperate grown rice (var. Jehlum): Numerical optimization, rheological and spectroscopic characteristics

This study aimed at optimizing process protocols for development of low glycemic index (GI) rice flour (LGIRF) by employing enzymatic hydrolysis method using central composite rotatable design (CCRD). LGIRF was evaluated for pasting, farinographic, spectroscopic and microbiological attributes. Independent variables for optimization included concentrations of α-amylase (0.02-0.12 %), glucoamylase (0.02-0.24 %), as well as the incubation temperature (55-80°C). Resistant starch (RS), glycemic index (GI) and glycemic load (GL) were investigated as response variables. The optimum conditions for development of LGIRF with better quality were- α-amylase concentration of 0.040 %, glucoamylase concentration of 0.070 % and an incubation temperature of 60 °C. The results of mineral analysis revealed significantly (p < 0.05) lower levels of boron, potassium, zinc, phosphorus, magnesium, and manganese in LGIRF, while iron and copper were significantly higher. The viscosity profile as evident from pasting profile and farinographic characteristics of LGIRF were significantly (p < 0.05) lower than native rice flour. 1H NMR and 13C NMR spectroscopic studies showed an increase in flexible starch segments and a decrease in amorphous portion of starch LGIRF, along with chemical shift alterations in carbons 1 and 4. Free fatty acids and total plate count were significantly (p < 0.05) higher in LGIRF although was within limits.

Recent advances in the impact of gelatinization degree on starch: Structure, properties and applications

During home cooking or industrial food processing operations, starch granules usually undergo a process known as gelatinization. The starch gelatinization degree (DG) influences the structural organization and properties of starch, which in turn alters the physicochemical, organoleptic, and gastrointestinal properties of starchy foods. This review summarizes methods for measuring DG, as well as the impact of DG on the starch structure, properties, and applications. Enzymatic digestion, iodine colorimetry, and differential scanning calorimetry are the most common methods for evaluating the DG. As the DG increases, the structural organization of the molecules within starch granules is progressively disrupted, the particle size of the granules is altered due to swelling and then disruption, the crystallinity is decreased, the molecular weight is reduced, and the starch-lipid complexes are formed. The impact of DG on the starch structure and properties depends on the processing method, operating conditions, and starch source. The starch DG affects the quality of many foods, including baked goods, fried foods, alcoholic beverages, emulsified foods, and edible inks. Thus, a better understanding of the changes in starch structure and function caused by gelatinization could facilitate the development of foods with novel or improved properties.

The multifactorial phenomenon of enzymatic hydrolysis resistance in unripe banana flour and its starch: A concise review

Unripe banana flour starch possesses a high degree of resistance to enzymatic hydrolysis, a unique and desirable property that could be exploited in the development of functional food products to regulate blood sugar levels and promote digestive health. However, due to a multifactorial phenomenon in the banana flour matrix-from the molecular to the micro level-there is no consensus regarding the complex mechanisms behind the slow enzymatic hydrolysis of unripe banana flour starch. This work therefore explores factors that influence the enzymatic hydrolysis resistance of raw and modified banana flour and its starch including the proportion and distribution of the amorphous and crystalline phases of the starch granules; granule morphology; amylose-amylopectin ratio; as well as the presence of nonstarch components such as proteins, lipids, and phenolic compounds. Our findings revealed that the relative contributions of these factors to banana starch hydrolytic resistance are apparently dependent on the native or processed state of the starch as well as the cultivar type. The interrelatability of these factors in ensuring amylolytic resistance of unripe banana flour starch was further highlighted as another reason for the multifactorial phenomenon. Knowledge of these factors and their contributions to enzymatic hydrolysis resistance individually and interconnectedly will provide insights into enhanced ways of extraction, processing, and utilization of unripe banana flour and its starch.

Gluten-free pasta as an alternative in the diet of patients with celiac disease

Celiac disease (CD) is an autoimmune disorder that produces inflammation in the gut mucosa, affecting nutrient digestion and absorption. CD affects 0.3% to 1.0% of the world's population and only 15% have a clinical diagnosis. The only effective treatment is a gluten-free diet. The objective of this study was to develop a dough for gluten-free pasta prepared with mixtures of flours from corn, amaranth, soy, and rice. According to the FAO standard of 1975, the resultant mixtures should have a protein content greater than 11.0% and a chemical rating of not less than 70. Three mixtures were obtained: corn‒soy (81-19), corn‒rice‒soy (48-37-15), and corn‒rice‒amaranth (49-32-14). To improve the handling of the pasta and its physical characteristics (sedimentation, degree of absorption, and cracked shaped pasta) compared to a control (commercial) gluten-free pasta, carboxymethylcellulose, an emulsifier (distilled monoglycerides), and egg albumin were added at concentrations of 0.3, 0.5, and 5.0%, respectively. The corn flour was pregelatinized, and the extrusion was repeated twice. The experimental pasta had a protein content of 14.0%, which was higher than the commercial pasta (4.5%), and a gluten content of less than 20 mg/kg which, according to the Codex Alimentarius International Food Standard (2015), it is considered gluten-free. The corn‒rice‒soy pasta obtained had an acceptance and liking similar to a commercial brand. This pasta may widen the gluten-free products commercially available to CD patients in Mexico, which nowadays is limited and expensive. PRACTICAL APPLICATION: Raw materials available in our country were selected to promote their consumption and diversify the ingredients used in the production of gluten-free products. The pasta obtained presented a higher nutritional content than a commercial gluten-free pasta and was comparable to that of a pasta made with wheat.

Moringa, Milk Thistle, and Jujube Seed Cold-Pressed Oils: Characteristic Profiles, Thermal Properties, and Oxidative Stability

Cold-pressed moringa, milk thistle, and jujube seed oils were investigated in terms of their characteristic profiles, thermal properties, and oxidative stability. The findings proved that the extracted oils were characterized by high nutritional values, which encourages their use in various fields. Results showed significant differences between the obtained oils. Overall, jujube seed oil exhibited the best quality parameters, with acidity equal to 0.762 versus 1% for the moringa and milk thistle seed oils. Milk thistle seed oil showed absorbance in the UV-C (100-290 nm), UV-B (290-320 nm), and UV-A (320-400 nm) ranges, while the moringa and jujube seed oils showed absorbance only in the UV-B and UV-A ranges. Concerning bioactive compounds, jujube seed oil presented the highest content of polyphenols, which promoted a good scavenging capacity (90% at 10 µg/mL) compared to the moringa and milk thistle seed oils. Assessing the thermal properties of the obtained oils showed the presence of four groups of triglycerides in the moringa and milk thistle seed oils, and two groups of triglycerides in the jujube seed oil. The thermograms were constant at temperatures above 10 °C for milk thistle seed oil, 15 °C for jujube seed oil, and 30 °C for moringa seed oil, which corresponded to complete liquefaction of the oils. The extinction coefficients K232 and K270, monitored during storage for 60 days at 60 °C, proved that jujube seed oil had the highest polyphenols content and was the most stable against thermal oxidation.

Effect of electric field on physicochemical properties and resistant starch formation in ohmic heating processed corn starch

This research investigated the impact of ohmic heating (OH) on the physicochemical properties and resistant starch formation in native corn starch. Electric field strengths (EFS) of 50, 75, and 100 V/cm were applied to native starch, at a starch-water ratio of 1:1 w/v. The conductivity of the medium is a crucial factor in ohmic heating. In this study, the conductivity values at 120 °C were measured at 1.5 mS/m. The study revealed two distinct outcomes resulting from the application of different EFS. Firstly, a thermal effect induced gelatinization, resulting in a reduction in the enthalpy of corn starch, an increase in the water absorption index (WAI) and the water solubility index (WSI), and a decrease in peak viscosity. Secondly, a non-thermal effect of OH was observed, leading to the electrolysis of certain starch compounds and water. This electrolysis process generated radicals (-OH) that interacted with starch components, augmenting the percentage of resistant starch. This increase was associated with elevated levels of carbonyl and carboxyl groups at 75 and 100 V/cm.

Understanding the physical breakdown and catechin bioaccessibility of third generation extruded snacks enriched with catechin using the human gastric simulator

The nutritional quality of third-generation snacks prepared from rice flour by extrusion can be improved by the addition of polyphenols such as catechins, which are known to be more stable at high temperatures. However, the extrusion parameters can impact the breakdown and release of bioactive compounds and decrease the catechin bioaccessibility. Accordingly, this study investigated the impact of different extrusion parameters, including different extrusion temperatures (110, 135, and 150 °C) and moisture content prior to extrusion (27 and 31%), on the breakdown and bioaccessibility of catechin-enriched snacks during in vitro dynamic digestion using the Human Gastric Simulator (HGS). The extrusion parameters did not significantly impact most measured variables by themselves, indicating that within the tested ranges, any of the processing conditions could be used to produce a product with similar digestive behavior. However, the interaction of extrusion parameters (temperature and moisture content) played a significant role in the snack behavior during digestion. For example, the combination of 27% moisture content and 150 °C extrusion temperature had higher catechin bioaccessibility and higher starch hydrolysis than the other treatments. Overall, these findings suggest that the processing conditions of third generation snacks enriched with catechin can be optimized within certain ranges with limited modifications in the digestive properties.

Effect of extrusion cooking on the chemical and nutritional properties of instant flours: a review

Satisfying the nutritional requirements of consumers has made food industries focus on the development of safe, innocuous, easy-to-prepare products with high nutritional quality through efficient processing technologies. Extrusion cooking has emerged as a prominent technology associated with the nutritional and functional attributes of food products. This review aims to establish a theoretical framework concerning the influence of extrusion parameters on the functional and nutritional properties of precooked or instant flours, both as end-products and ingredients. It highlights the pivotal role of process parameters within the extruder, including temperature, screw speed, and raw materials moisture content, among others, and elucidates their correlation with the modifications observed in the structural composition of these materials. Such modifications subsequently induce notable changes in the ultimate characteristics of the food product. Detailed insights into these transformations are provided within the subsequent sections, emphasizing their associations with critical phenomena such as nutrient availability, starch gelatinization, protein denaturation, enhanced in vitro digestibility, reduction in the content of antinutritional factors (ANFs), and the occurrence of Maillard reactions during specific processing stages. Drawing upon insights from available literature, it is concluded that these effects represent key attributes intertwined with the nutritional properties of the end-product during the production of instant flours.

Impact of moisture content on microstructural, thermal, and techno-functional characteristics of extruded whole-grain-based breakfast cereal enriched with Indian horse chestnut flour

The use of non-conventional seed flour is of interest in obtaining healthy breakfast cereals. The research aimed to study the physico-functional, bioactive, microstructure, and thermal characteristics of breakfast cereals using scanning electron microscopy, X-ray diffractometry, and differential scanning calorimeter. The increase in feed moisture content (16 %) enhanced the bulk density (5.24 g/mL), water absorption index (7.76 g/g), total phenolic content (9.03 mg GAE/g), and antioxidant activity (30.36 %) having desirable expansion rate (2.84 mm), water solubility index (48 %), and color attributes. The microstructure showed dense inner structures with closed air cells in extruded flours. Extrusion treatment rearranged the crystalline structure from A-type to V-type by disrupting the granular structure of starch, reducing its crystallinity, and promoting the formation of an amylose-lipid complex network. Increasing conditioning moisture enhanced the degree of gelatinization (%), peak gelatinization temperature (Tp), and starch crystallinity (%) and reduced the gelatinization enthalpy (ΔHG) and gelatinization temperature ranges. The results reported in this study will help industries to develop innovative and novel food products containing functional ingredients.

Effect of extrusion process on the obtention of a flour from coffee pulp Coffea arabica variety red Caturra and its use in bakery products

The main waste in the coffee industry is the coffee pulp (CP), an interesting source of fiber and phenolic compounds. An alternative for its harnessing can be its transformation into a flour for human consumption, generating added value for a circular economy. The aim of this study was to obtain flour from CP (CPF) using extrusion and the evaluation of its incorporation into a bakery product. Extrusion treatments to get a flour were explored by a factorial design 23, considering the temperature, moisture, and extruder screw revolutions (rpm). Treatments were evaluated for their effects on the proximal composition, phytic acid, caffeine, and phenolic compounds contents of the flours, and baking characteristics such as water absorption (WAI) and water solubility index (WSI). Once the best extrusion treatment was selected, bread formulations were developed, two wheat-based and two gluten-free, which were evaluated using "Flash Profiling". Extrusion treatment 110 °C, 35% moisture, and 17.5 rpm, was selected as the best one to get a flour with good functional properties (WAI:2.94 ± 0.13, WSI:21.02 ± 3.27) and a content of phenolic compounds: 55.14 mg/g and caffeine:14.23 mg/g. Sensorially, good acceptance, up to 15% substitution by flour, was achieved. Extruded CPF could be a food ingredient, at least in bakery products, contributing in the practice of a circular economy.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-023-05797-x.

Effect of extrusion processing on techno-functional properties, textural properties, antioxidant activities, in vitro nutrient digestibility and glycemic index of sorghum-chickpea-based extruded snacks

Physico-chemical, textural, functional, and nutritional properties of the twin screw extruded whole sorghum-chickpea (8:2) snacks was investigated using in vitro procedures. The extruded snacks were analyzed for the effect of variations in extruded conditions on their properties: barrel BT (BT) (130-170°C) and feed moisture (FM) (14%-18%), keeping screw speed constant (400 rpm). The results revealed that specific mechanical energy (SME) decreased (74.4-60.0) in response to rise in both BT and FM, whereas expansion ratio (ER) had shown an alternative relation as it decreased with elevated FM (2.17 at 14%, 130°C to 2.14 at 16%, 130°C) and increased with BT (1.75 at 18%, 130°C to 2.48 at 18%, 170°C). The values of WAI and WSI improved with the surge in BT, which was associated with enhanced disruption of starch granules at higher BT. Raise in FM incremented the total phenolic content (TPC) and hence the antioxidant activity (AA) (FRAP and DPPH) along with the hardness of snacks. As per in vitro starch digestibility is concerned, slowly digestible starch (SDS) content as well as glycemic index (51-53) of the extrudates depressed with increasing BT and FM. Also, lower BT and FM improved the functional properties such as expansion ratio, in-vitro protein digestibility, and overall acceptability of the snacks. A positive correlation was seen among SME and hardness of the snacks, WSI and ER, TPC and AA, SDS and Exp-GI, color and OA, texture and OA.

Green banana biomass (Musa spp.) as a natural food additive in artisanal tomato sauce

This study aimed to prepare artisanal tomato sauce (TSC, control) containing 10% (TS10) or 20% (TS20) of whole green banana biomass (GBB). Tomato sauce formulations were evaluated for storage stability, sensory acceptability, and color and sensory parameters correlations. Data were subjected to Analysis of Variance, followed by the comparison of means by Tukey's test (p < 0.05 and p < 0.01). Correspondence analysis was used to assess the responses to a Check-All-That-Apply questionnaire. A significant effect was observed (p > 0.05) for the interaction between storage time and GBB addition on all physicochemical parameters. GBB reduced titratable acidity and total soluble solids (p < 0.05), possibly because of its high content of complex carbohydrates. All tomato sauce formulations had adequate microbiological quality for human consumption after preparation. Sauce consistency increased with increasing GBB concentrations, improving the sensory acceptance of this attribute. All formulations achieved the minimum threshold for overall acceptability (70%). A thickening effect was observed with the addition of 20% GBB, resulting in significantly (p < 0.05) higher body, higher consistency, and reduced syneresis. TS20 was described as firm, very consistent, light orange in color, and very smooth. The results support the potential of whole GBB as a natural food additive.

Techno-functional properties of gluten-free pasta from hyperprotein quinoa flour

Many consumers who are aware of the importance of good nutrition demand quality food alternatives. In particular, many of them are looking for quality, plant-based protein sources such as quinoa. The objective of this work was to evaluate the techno-functional properties of gluten-free pasta from hyperprotein quinoa flour. Pasta mixes were made from gluten-free flours, corn, rice, cassava starch, hyperprotein quinoa flour and defatted high protein quinoa flour, which were subsequently extruded. The flow rheological properties of aqueous dispersions of flour mixtures were analyzed before and after the pasting test. In addition, thermal properties were analyzed by differential scanning calorimetry and structural properties by Fourier transform infrared spectroscopy. The results showed a change of flow from dilatant (n > 1) to pseudoplastic (n < 1) after the pasting test. In addition, a positive correlation was observed between hyperprotein defatted quinoa flour and viscosity, and a negative correlation with hyperprotein quinoa flour. Regarding thermal properties, it was found that all blends showed low gelatinization enthalpy values, attributed to the high proportions of HQF and HDQF. Spectroscopic analysis showed that the extrusion did not significantly affect the native structure of the protein, by monitoring the intensities of the 1648 cm-1, 1656 cm-1 and 1667 cm-1 bands associated with the Random coil, α-helix, β-turns secondary structures, respectively. It was possible to conclude that both hyperprotein quinoa flour and defatted hyperprotein quinoa flours have a differential influence on the techno-functional properties of pasta. The first one, tends to reduce viscosity and consistency while the second one tends to increase it. Finally, moderate temperatures during extrusion did not cause significant changes in starch and protein structures as determined by spectroscopic study.

Functional properties and in vitro starch digestibility of infrared-treated (micronized) green banana flour

BACKGROUND

The consumption of green banana flour (GBF) products has been linked to reduced glycemic index (GI) and low risk of type 2 diabetes and obesity. The purpose of this study was to investigate the effect of micronization (high-intensity infrared heating method) on the molecular, microstructure and in vitro starch digestibility of five GBF cultivars grown in South Africa. The GBF was micronized at three surface temperatures (90, 120 and 150 °C for 30 min) and the in vitro starch digestibility was determined with Megazyme kits.

RESULTS

Micronization at the highest temperature (150 °C) increased the swelling power by 6.00% in all five GBF cultivars when compared to control (unmicronized GBF). Micronization slightly reduced the resistant starch (RS) of the GBF cultivars by up to 8.63%. The FHIA-01 cultivar showed the highest RS (86.50%), whereas Grande Naine - 150 °C cultivar had the lowest RS (76.00%). Both micronized and control GBF exhibited similar X-ray diffraction patterns with all cultivars and at all micronization temperatures. Similarly, the functional properties of the GBF were not altered by micronization when observed with Fourier transform infrared spectroscopy. Scanning electron microscopy showed changes in the surface morphology of starch granules after micronization and these were dependent on temperature.

CONCLUSION

Overall, micronization at 120 °C showed the best improvement in functional properties of GBF and this makes it suitable for potential application for the manufacture of instant breakfast products, baked goods and pasta. In addition, the micronized GBF cultivars retained high RS, suggesting potential health benefits for people with diabetes and obesity. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Study of unripe and inferior banana flours pre-gelatinized by four different physical methods

This study aimed to prepare the pre-gelatinized banana flours and compare the effects of four physical treatment methods (autoclaving, microwave, ultrasound, and heat-moisture) on the digestive and structural characteristics of unripe and inferior banana flours. After the four physical treatments, the resistant starch (RS) content values of unripe and inferior banana flours were decreased from 96.85% (RS2) to 28.99-48.37% (RS2 + RS3), while C∞ and k values were increased from 5.90% and 0.039 min^-1 to 56.22-74.58% and 0.040-0.059 min^-1, respectively. The gelatinization enthalpy (ΔHg) and I_1047/1022 ratio (short-range ordered crystalline structures) were decreased from 15.19 J/g and 1.0139 to 12.01-13.72 J/g, 0.9275-0.9811, respectively. The relative crystallinity decreased from 36.25% to 21.69-26.30%, and the XRD patterns of ultrasound (UT) and heat-moisture (HMT) treatment flours maintained the C-type, but those samples pre-gelatinized by autoclave (AT) and microwave (MT) treatment were changed to C + V-type, and heat-moisture (HMT) treatment was changed to A-type. The surface of pre-gelatinized samples was rough, and MT and HMT showed large amorphous holes. The above changes in structure further confirmed the results of digestibility. According to the experimental results, UT was more suitable for processing unripe and inferior banana flours as UT had a higher RS content and thermal gelatinization temperatures, a lower degree and rate of hydrolysis, and a more crystalline structure. The study can provide a theoretical basis for developing and utilizing unripe and inferior banana flours.

Extrusion Modification of Wheat Bran and Its Effects on Structural and Rheological Properties of Wheat Flour Dough

The study investigated the extrusion modification of wheat bran and its effects on structural and rheological properties of wheat flour dough. Extruded bran showed better solubility of dietary fiber and structural porosity, leading to higher hydration and swelling power. Addition of extruded bran to dough caused water redistribution as an intensive aggregation of bound water to gluten matrix with reduced mobility. The bran-gluten interaction influenced by water sequestering caused partial gluten dehydration and conversion of β-turn into β-sheet, which demonstrated the formation of a more polymerized and stable gluten network. Farinographic data confirmed the promotion of dough stability with extruded bran addition at lower gluten content, while viscoelastic data suggested improved dough elasticity at all gluten contents by increasing elastic moduli and decreasing loss tangent. This study would be useful for interpreting the modification effect and mechanism of extrusion on cereal brans and provide valuable guidance for applying it as an effective modification technology on the commercial production of cereal bran and its flour products.

Corn Extrudates Enriched with Health-Promoting Ingredients: Physicochemical, Nutritional, and Functional Characteristics

The objective of this study was to evaluate the effects of different types of powder additions on the properties of corn extrudates. The following ingredients, which are good sources of bioactive compounds, were used to substitute corn flour: legume protein sources (2% pea, 5% broccoli, and 5% lucerne), plants (15% beetroot and 15% rosehip), and condiments (2% chili, 2% turmeric, 2% paprika, and 2% basil). The total polyphenolic content (TPC) and antioxidant activity (AA) increased when the corn flour was replaced with the different types of ingredients. The highest TPC was found for rosehip followed by the beet, basil, and broccoli additions. Compared to the raw formulations, all the extrudates, except the rosehip extrudate, showed a decrease in the TPC ranging from 11 to 41%, with the smallest loss (11%) occurring for basil and the highest loss (41%) occurring for the control extrudate, respectively. The same observation was recorded for the AA. For the extrudate enriched with rosehip, the TPC and AA increased by 20% and 16%, respectively. The highest level of protein digestibility was in the corn extrudate with the pea addition followed by broccoli and lucerne. The extruded corn samples with condiment additions had a lower glycemic index than the control extrudate. This study demonstrated the potential for the production of gluten-free corn extrudates enriched with ingredients from different sources with improved nutritional properties, conferring also a natural color in the final extrudates.

Techno-Functional Properties of Corn Flour with Cowpea (Vigna unguilata) Powders Obtained by Extrusion

Legumes are a good source of vegetal protein that improves diets worldwide. Cowpea has been used as fortification agents in some traditional corn foods in developing countries such as Colombia. The work aimed to evaluate the physicochemical properties of extruded mixtures of corn and cowpea flours to assess the use of these mixes as vegetable protein ingredients. Corn flour was mixed with 15, 30, and 50% of cowpea flour and extruded for this proposal. After extrusion, mixtures were ground to produce a powder. Techno-functional properties of powders as water content, hygroscopicity, water absorption, fat absorption, water solubility index, swelling index, bulk density, Hausner ratio, Carr index, and porosity were evaluated in the mixtures, extrudates, and obtained powders to assess the effect of the addition of cowpea on these properties. Results showed that processing powder obtained by extrusion and drying could be used as a powder to regenerate with water as a source of protein. Moreover, storing processing samples in sections (pellet format) is convenient to avoid wetting since this format is less hygroscopic and the same mass occupies less storage volume than powders.

Effect of new type extrusion modification technology on supramolecular structure and in vitro glycemic release characteristics of starches with various estimated glycemic indices

Nowadays, the highly effective modified technology to starch with various digestibility is gaining interest in food science. Here, the interactions between glycemic release characteristics and fine supramolecular structure of cassava (ECS), potato (EPS), jackfruit seed (EJFSS), maize (EMS), wheat (EWS), and rice starches (ERS) prepared with improved extrusion modification technology (IEMS) were investigated. The crystalline structures of all extruded cooking starches changed from the A-type to V-type. IEMS-treated cassava, potato, and rice starches had broken α-1.6-glycosidic amylopectin (long chains). The others sheared α-1.4-glycosidic amylopectin. The molecular weight, medium and long chain counts, and relative crystallinity decreased, whereas the number of amylopectin short chains increased. The glycemic index (GI) and digestive speed rate constant (k) of ECS, EPS, EJFSS, and EWS were improved compared to those of raw starch. Although EMS and ERS had degraded molecular structures, their particle morphology changed from looser polyhedral to more compact with less enzymolysis channels due to the rearrangement of side chain clusters of amylopectin, leading to enzyme resistance. The starch characteristics of IEMS-treated samples significantly differed. EPS had the highest amylose content, medium chains, long chains, and molecular weight but lowest GI, relative crystallinity, and k. ERS showed the opposite results. Thus, IEMS may affect starches with different GIs to varying degrees. In this investigation, we provide a basis for wider applications of conventional crop starch in the food industry corresponding to different nutrition audience.

Effects of Extrusion on Starch Molecular Degradation, Order-Disorder Structural Transition and Digestibility-A Review

Extrusion is a thermomechanical technology that has been widely used in the production of various starch-based foods and can transform raw materials into edible products with unique nutritional characteristics. Starch digestibility is a crucial nutritional factor that can largely determine the human postprandial glycemic response, and frequent consumption of foods with rapid starch digestibility is related to the occurrence of type 2 diabetes. The extrusion process involves starch degradation and order-disorder structural transition, which could result in large variance in starch digestibility in these foods depending on the raw material properties and processing conditions. It provides opportunities to modify starch digestibility by selecting a desirable combination of raw food materials and extrusion settings. This review firstly introduces the application of extrusion techniques in starch-based food production, while, more importantly, it discusses the effects of extrusion on the alteration of starch structures and consequentially starch digestibility in various foods. This review contains important information to generate a new generation of foods with slow starch digestibility by the extrusion technique.

Effects of extrusion temperature and puffing technique on physical and functional properties of purpled third-generation snack after heat treatment

This work aimed to investigate the effects of extrusion temperature (100 105 and 110 °C) and puffing technique (microwaving (210, 420 and 560 W.) and deep frying (170 and 190 °C)) on physical and functional properties of third-generation snack containing purple sweet potato and butterfly pea flower. Snack qualities in terms of physical properties (expansion ratio, bulk density, color and texture) and functional properties (total anthocyanin content, total phenolic content and antioxidant capacity) were subsequently determined. The results showed that extrusion temperature did not significantly affect the color of snack pellets. However, it significantly affected the functional properties of the snack pellets. Snack pellet produced from extruder at 110 °C contained significantly higher functional properties when compared to those extruded at 100 and 105 °C (p < 0.05). In addition, the study of the puffing method indicated that an increase of microwave power level and frying temperature resulted in a decrease of hardness. On the other hand, the increase of microwave power level and frying temperature caused an increase of antioxidant capacity in the puffed snacks. Moreover, microwave puffing could help preserve the color and antioxidant capacity better than deep frying. Especially, microwaved snack had total anthocyanin content twice more than that puffed by frying.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-021-05234-x.

Physical and Paste Properties Comparison of Four Snacks Produced by High Protein Quinoa Flour Extrusion Cooking

Extrusion cooking is used to produce puffed snacks based on cereals and feed ingredients. Because of its nutritional properties, quinoa flour has been employed to prepare various types of foods. This study evaluates the effects of including hyper-protein quinoa flour obtained through abrasive milling in four formulations cooked at 27% moisture content and processed in a laboratory level single screw extruder to determine their physical, textural, and pasting properties. The results indicated that additional hyper-protein quinoa flour in the cereal mixture reduced 47% the expansion index (EI), while the extrudate density (ED) and hardness increased 54 and 130%, respectively. After the extrusion process, the water absorption index (WAI), water solubility index (WSI) increased by more than 100%. The addition of hyper-protein quinoa flour (25–37%) did not affect the WAI, but an increase in the WSI was observed. The quinoa flour extrusion process generated changes on the color mainly in the L parameter, which decreased in the extruded snacks with quinoa flour inclusion (51.49), compared to the snack without inclusion (62.68). Changing the integrity of the starch granules and associated proteins, causing a decrease in the viscosity peaks during heating and subsequent cooling. The extruded samples revealed stability in the retrogradation process. Extruded snacks from quinoa could be an alternative approach to produce feed ingredients with high protein contents.

Lactose-free dulce de leche with different concentrations of green banana biomass

Abstract The production and consumption of dulce de leche is one of the most important sweets in the Mercosul Region. However, recent studies have shown consumers’ interest for healthier food and no lactose products, hence creating a demand for this study aims to develop a more nutritional lactose-free dulce de leche with less calories and higher yielding by adding green banana biomass. Five lactose-free dulce de leche formulas have been elaborated in which four were added 5%, 10%, 15% and 20% of green banana biomass and one of them received a standard 0.5% of commercial starch addition. The samples were evaluated regarding its microbiological, physicochemical and sensorial quality. The different lactose-free dulce de leche formulas attended the microbiological standards and demonstrated an increased yield of the green banana biomass concentration. The results indicated that the rise of the green banana biomass concentration has increased moisture and decreased protein, lipids and calories levels. In regards of acceptance, all samples evaluated received grades between 7.23 to 8.72, that is, above 6 which is the minimum value accepted to all the evaluated attributes hence demonstrating the acceptance on behalf of evaluators. All samples presented high ratios of intent to purchase therefore confirming the acceptance results found. It has been observed that the use of green banana biomass aggregated positive characteristics to the product and did not influence the sensorial quality of the sweets, seeing that all of them could improve their yield and thus demonstrating to be a good option to the development of healthier products.

Rapid spectroscopic method for quantifying gluten concentration as a potential biomarker to test adulteration of green banana flour

The demand for gluten-free banana flour has led manufactures to enforce strict measures for quality control. A need has arisen for the development of more sensitive and reliable methods to test the quality of green banana flour (GBF). The objective of this study was to develop rapid visible to near-infrared (Vis-NIR) based spectroscopic models to detect gluten concentration, as a biomarker to detect wheat flour adulteration in green banana flour (GBF). Spectroscopic data were acquired using a desktop (FOSS®) Vis-NIR spectroscopy ranging from 400 to 2500 nm of the electromagnetic spectrum. The spectral and reference data were submitted to principal component analysis (PCA) and partial least squares regression (PLSR) for the development of gluten adulteration detection models. Calibration models were constructed based on a full cross-validation approach, consisting of 51 samples for the calibration set and 21 samples for the test set. PCA scores plot discriminated gluten adulterated and unadulterated GBF samples with 100% accuracy for the first two principal components (PCs). The optimal prediction model was obtained after a combination of baseline (offset and baseline linear correlation) and standard normal variate (SNV) pre-processing technique. This model showed a 94% coefficient of determination of cross-validation (R²_cv) and prediction (R²_p); root mean square error of cross-validation (RMSECV) of 3.7 mg/kg, root mean square error of prediction (RMSEP) of 3.9 mg/kg; and RPD value of 4. This work has demonstrated that Vis-NIRS method is a robust and feasible technology that may be used to ensure the safety of banana flour and that this product stays gluten-free by providing good and reliable gluten detection and quantification prediction models.

A draft genome, resequencing, and metabolomes reveal the genetic background and molecular basis of the nutritional and medicinal properties of loquat (Eriobotrya japonica (Thunb.) Lindl)

Loquat (Eriobotrya japonica) is a popular fruit and medicinal plant. Here, a high-quality draft genome of the E. japonica 'Big Five-pointed Star' cultivar that covers ~98% (733.32 Mb) of the estimated genome size (749.25 Mb) and contains a total of 45,492 protein-coding genes is reported. Comparative genomic analysis suggests that the loquat genome has evolved a unique genetic mechanism of chromosome repair. Resequencing data from 52 loquat cultivars, including 16 white-fleshed and 36 yellow-fleshed variants, were analyzed, and the flower, leaf, and root metabolomes of 'Big Five-pointed Star' were determined using a UPLC-ESI-MS/M system. A genome-wide association study identified several candidate genes associated with flesh color in E. japonica, linking these phenotypes to sugar metabolism. A total of 577 metabolites, including 98 phenolic acids, 95 flavonoids, and 28 terpenoids, were found, and 191 metabolites, including 46 phenolic acids, 33 flavonoids, and 7 terpenoids, showed no differences in concentration among the leaves, roots, and flowers. Candidate genes related to the biosynthesis of various medicinal ingredients, such as phenolics, flavonoids, terpenoids, and polysaccharides, were identified. Some of these genes were confirmed to be members of expanding gene families, suggesting that the high concentrations of beneficial metabolites in loquat may be associated with the number of biosynthetic genes in this plant. In summary, this study provides fundamental molecular insights into the nutritional and medical properties of E. japonica.

Changes in Phenolics during Cooking Extrusion: A Review

In this paper, significant attention is paid to the retention of phenolics in extrudates and their health effects. Due to the large number of recent articles devoted to total phenolic content (TPC) of input mixtures and extrudates, the technological changes are only presented for basic raw materials and the originating extrudates, and only the composites identified has having the highest amounts of TPC are referred to. The paper is also devoted to the changes in individual phenolics during extrusion (phenolic acids, flavonoids, flavonols, proanthocyanidins, flavanones, flavones, isoflavons, and 3-deoxyanthocyanidins). These changes are related to the choice or raw materials, the configuration of the extruder, and the setting the technological parameters. The results found in this study, presented in the form of tables, also indicate whether a single-screw or twin-screw extruder was used for the experiments. To design an extrusion process, other physico-chemical changes in the input material must also be taken into account, such as gelatinization of starch; denaturation of protein and formation of starch, lipids, and protein complexes; formation of soluble dietary fiber; destruction of antinutritional factors and contaminating microorganisms; and lipid oxidation reduction. The chemical changes also include starch depolymerization, the Maillard reaction, and decomposition of vitamins.

Reformulation of Muffins Using Inulin and Green Banana Flour: Physical, Sensory, Nutritional and Shelf-Life Properties

This study demonstrates a scenario of industrial reformulation by developing muffins that resemble store-branded ones and testing the possibility of reformulating them using inulin and green banana flour (GBF). Ten different formulations were created through reducing 10% or 30% of sugar and/or fat. Physical characteristics, consumer acceptance and purchase preferences, baking losses, nutritional properties, shelf-life, as well as cost and industrial processability were considered and discussed. Results on physical properties showed that firmness had increased in reformulated muffins while springiness only decreased when both sugar and fat were reduced by 30% (p < 0.05). Texture and sensory properties of reformulated muffins were acceptable, and the purchase intent rate was high. Regarding the nutritional properties, muffins incorporating more than 10% of fibres allowed the addition of nutritional claims. The incremental area under the curve iAUC_120min of blood glucose in healthy adults (n = 13) was significantly lower than control after ingesting 30% reduced sugar or fat muffins using inulin (p < 0.01). The microbial profile was not affected by reformulation during storage at 25 °C for 10 days. This study concluded that there is a significant potential to industrially produce reduced sugar or fat muffins using inulin or GBF up to 30% without significantly deteriorating quality attributes.

Lactobacillus acidophilus and Non-Digestible Carbohydrates: A Review

In the recent years, lactic acid bacteria species such as Lactobacillus are considering one of the important species of probiotics used in the food processing sector to produce fermented products and play a significant role for the transformation and preservation of food products. Besides, there is a huge exploration of new molecules that promote health and exhibit potential for technological applications such as non-digestible carbohydrates. The non-digestible carbohydrates provide various health benefits such as balancing and sustaining the microbiota in the intestine and increasing the production of short chain fatty acids (SCFA). The aim of this review is to review some types of non-digestible carbohydrates as an enhancer for the growth of probiotics. These compounds can help in improving many characteristics of food such as sensory and textural properties.

Properties of Extruded Snacks Prepared from Corn and Carrot Powder with Ascorbic Acid Addition

The objective of this research was to investigate the potentiality of carrot powder (CP) utilization at levels 4, 6, or 8% as ingredient of corn snacks and evaluation of the extrusion influence on functionally important ingredients such as carotenoids (color), polyphenols, fiber, fat, and antioxidant activity. The influence of ascorbic acid (AA) as an external source at levels 0.5 and 1% on this particular extrusion was also investigated. A single-screw extruder at two temperature regimes (135/170/170 °C (E1) and 100/150/150 °C (E2)) carried out extrusion. The E1 temperature regime acted favorably on total polyphenol content and crude fiber, but fat preferred the E2 regime. Extrusion, especially the E1 temperature regime, increased the extractability of carotenoids. Ascorbic acid degraded during extrusion, but it still provided protection to carotenoids and color attributes of extrudates. Snacks with increased nutritional and functional value due to carrot powder addition were successfully produced, which is a starting point for production of a new type of extruded snacks.

Heating-cooling extrusion cycles as a method to improve the physicochemical properties of extruded corn starch

This work proposed a controlled method to modify the physicochemical properties of corn starch through heating and cooling extrusion (HCE) cycles. It was used native corn starch adjusted to 60% moisture. It was then subjected to 5 HCE cycles at 100 and 125 °C, at 10 rpm. Water absorption index (WAI), water solubility index (WSI), resistant starch (RS), thermal properties, viscosity, FTIR, and X-ray were evaluated. For WAI and WSI, a gradual increase was observed on each HCE cycle. Thermal properties shown that enthalpy decrease with each HCE cycles due to more gelatinization. Viscosity properties shown a thermally stable starch conditions being directly proportional to HCE cycles. The RS increased for each 5 HCE. XRD revealed that HCE cycle changed the starch structure from an orthorhombic structure to V-type crystalline structure. Finally, it was concluded that HCE cycles is a method to produce corn starch with controlled physicochemical properties.

Effect of temperature and particle size on physicochemical and techno-functional properties of peach palm peel flour (Bactris gasipaes, red and yellow ecotypes)

In this study, the effect of temperature and particle size on the techno-functional properties of the flour from peach palm fruit peels (Bactris gasipaes, red and yellow ecotype) were evaluated. The flour from peach palm epicarp obtained by natural convective drying was physicochemically characterized, including the assessment of total dietary fiber determined under the gravimetric enzymatic method. The results obtained showed that temperature and particle size present a significant effect (p < 0.001) on techno-functional properties except for swelling capacity. The flour from the red ecotype presented better nutritional: total dietary fiber 47.93 ± 1.72%, protein 6.87 ± 0.15% and techno-functional properties: water retention capacity (WRC) 7.13 ± 0.29 g/g, oil retention capacity (ORC) 6.24 ± 0.08 g/g, emulsifier activity (EA) 56.84 ± 0.28%, emulsifier stability (ES) 50.33 ± 0.31% than the yellow one water absorption capacity (WAC) 5.31 ± 0.03 g/g and water solubility (WS) 59.58 ± 0.04% at 60 °C and 0.25 mm. Therefore, this study showed that the flour obtained from peach palm fruit peels contains high fiber and protein values and could be used as a promising natural additive (source of dietary fiber or emulsifier) for the food industry.