Rice flour physically modified by microwave radiation improves viscoelastic behavior of doughs and its bread-making performance

Producción CientíficaThe physical modification of rice flour by heat-moisture treatment assisted by microwave radiation and its effect on the rheological and pasting properties of gluten-free doughs and the physical quality of their resulting bread was investigated. Two levels of flour initial moisture content, 20% (MW-20%) and 30% (MW-30%) and two levels of its addition (30% and 50%) to the dough were evaluated to assess the potential of the physical treatment to modify dough viscoelasticity and bread-making ability. MW-30% treated rice flour showed the most notable results. It provided enhanced dough viscoelasticity vs the control (100% native rice flour), increasing the dough G1′ modulus up to 69% and 135% for the treated flour additions of 30% and 50% of MW-30% respectively. The treated flour increased the resistance of doughs to deformation and enhanced their elastic behavior and recovery capacity up to 170% when compared to the control dough. The major effects on pasting parameters were also obtained for the doughs formulated with MW-30% flour at the maximum substitution level (50%). It delayed the pasting temperature, decreased the peak, trough and final viscosities with respect to the control dough. Both MW-treated rice flours (MW-20% and MW-30%) led to bread with higher-specific volume, softer crumb and delayed staling. The MW assisted heat moisture treatment of rice flour seems to be a valuable procedure to improve the viscoelastic behavior and bread-making performance of gluten-free doughs.Ministerio de Economía y Competitividad and the European Regional Development Fund (FEDER) - AGL2015-63849-C2-2-RJunta de Castilla y León and FEDER - VA072P17European Commission for the Individual Fellowship Grant - 706102–BreadForAl

Microwave radiation and protein addition modulate hydration, pasting and gel rheological characteristics of rice and potato starches

Producción CientíficaThis study evaluated for first time the effect of Microwave (MW) radiation on systems based on potato and rice starches supplemented with 5% of calcium caseinate (CA) or soy protein isolate (SPI). The goal of this treatment was the physical modification of these starch-based systems to provide ingredients of new functionalities. The hydration and pasting properties as well as gel viscoelastic features were evaluated. Dynamic oscillatory rheological tests were used. The effect of MW treatment (MWT) depended on the starch botanical origin and was significantly affected by protein presence and type. MWT of starch + protein blends revealed the most notable changes when SPI was added. Adding it to rice starch decreased swelling power (-45%), altered viscometric profiles and reinforced gel structure with important increases in both viscoelastic moduli (+160%-G’ and +58%-G’’). In blends with potato starch, MWT increased water absorption capacity (+115%) and decreased water solubility index (-82%). MWT of protein-potato blends promoted gel stability, decreased their pasting profiles and resulted in enhanced viscoelastic moduli (+483-G’ and 243%-G’’). MWT combined with protein addition allows designing starch-based foods with tailored properties.Ministerio de Economía y Competitividad - FEDER (AGL2015-63849-C2-2-R)Junta de Castilla y León - FEDER (VA072P17

Microwave absorption capacity of rice flour. Impact of the radiation on rice flour microstructure, thermal and viscometric properties

Producción CientíficaThe microwave radiation thermal treatment of rice flour was studied and its impact on physical and structural characteristic in relation to the initial moisture content (IMC) (20% and 30%) was evaluated. To explain the fundamentals of observed changes the microwave radiation absorption capacity of flour as well as temperature and moisture change during the treatment were evaluated. The flour particle morphological structure as well as crystallinity/amorphous region ratio changed after the treatment. The flour thermal properties also altered revealing IMC significant impact on the gelatinization temperature, that raised up to 3 C, and the amylopectin retrogradation extent that increased up to a 7% in the most intense microwave-treated flours with respect to the native flour. Lower peak, setback and breakdown viscosities - that decreased with respect to the native flour up to 42%, 34% and 86% respectively-and higher pasting temperatures -that increased up to 10 ºC- were also observed. An exceptional microwave irradiation efficiency resulting in rice flour physical changes in significantly shorter times, 4e8 min, than conventional heat-moisture treatment processes was concluded.Ministerio de Economía, Industria y Competitividad (Proyect AGL2015-63849-C2-2-R)Junta de Castilla y León (programa de apoyo a proyectos de investigación – Ref. VA072P17

Proteinaceous Residue Removal from Oat β-Glucan Extracts Obtained by Alkaline Water Extraction

Background: Wet methods of 1-3, 1-4 -β-D-glucan isolation from cereals differ mainly in the type of grain fraction used as raw material, the solid-liquid ratio of β-glucan in raw material vs. solvent used, and the type of aqueous solvent modification (alkali, neutral or acidic). All these factors impact the characterization of the residues finally found in extracts. Oat bran is a rich source of globulin fraction which can be transferred into the extracts, especially when a high pH is employed. Methods: A multi-stage (enzymatic and acidic) purification procedure was performed to remove the residues, especially starch and protein, from β-glucan isolates from oat of different molar mass. Pancreatin, thermostable α-amylase, amyloglucosidase, and papain were used for consecutive residue removal. Three levels of low pH = 4.5, 3.5 and 3.0 were also tested for effective protein precipitation. Results: The starch hydrolysis and liquefaction significantly facilitate the proteinaceous matter removal although papain usage showed an intensive unfavorable impact on β-glucan molar mass. Soluble protein content was significantly decreased after pancreatin and α-amylase treatment, while the significant reduction of amine nitrogen was noted after complete starch hydrolysis and a second acidification step. Conclusions: A complex procedure employing different enzymes is needed to successfully reduce the possibly bioactive residues in isolated oat β-glucan fractions

Acerola (<i>Malpighia emarginata</i>) Anti-Inflammatory Activity—A Review

The manuscript provides an overview of recent scientific reports on the properties and range of health-promoting effects of acerola (Malpighia emarginata DC) fruits and leaves. Acerola is a natural raw material that, in its unprocessed form, is known to be a rich source of vitamin C and polyphenolic compounds. For this reason, the consumption of acerola may provide a number of health-promoting benefits, particularly related to its strong anti-free radical effects. The review discusses anti-inflammatory and anticancer effects of acerola fruit and leaves as well as its therapeutic effects on selected physiological processes in the human system. Their biochemical mechanisms are also explained. Recommendations for the consumption of acerola in the prevention of inflammatory and free radical diseases are presented. The part of the article devoted to anticancer effects of acerola describes the possibilities of using the edible parts of this raw material to obtain products and preparations of potential use in cancer prevention and therapy

Functional and Antioxidative Characteristics of Soft Wheat and Tiger Nut (<i>Cyperus esculentus</i>) Flours Binary Blends

Tiger nut (Cyperus esculentus) or chufa is little known plant of high nutritious content. Popularized by a plant-based drink called “horchata de chufa,” it still offers a lot to research, being abundant in fat, starch, fiber and minerals and vitamins. To properly adjust this raw material to new purposes, the knowledge of crucial properties of the most basic blends like with soft wheat flour is needed. This article evaluates the techno-functional, viscometrical and bioactive characteristics of soft wheat:tiger nut blends of 5%, 10%, 15%, 20% and 25%. Granulometry, water-holding capacity (WHC), water absorption capacity (WAC), water absorption index (WAI), water solubility index (WSI), oil absorption capacity (OAC), hydrophilic/lipophilic index (HLI), color, pasting properties, total polyphenol content (TPC), antioxidant activity (DPPH), reducing sugars content and dough-rising capacity were assessed. The addition of tiger nut improved total polyphenol content of blends, however, It was observed that the addition of tiger nuts raised the total polyphenol content of the mixtures, but this was not statistically significant despite as much as 25% of tiger nuts. Oppositely, antioxidant activity was gradually improved with increasing tiger nut content. Pasting properties were impacted by tiger nut addition, lowering both pasting viscosity and trough viscosity, however, final viscosity was not particularly affected, being lowered by less than 15%. The highest water absorption was noted for 100% tiger nut both for WHC and WAC, however, WAI was the lowest for this sample. All the blends with tiger nut revealed improved dough-rising profile

Natural Gums as Oleogelators

The natural gums used as high molecular weight oleogelators are mainly polysaccharides that deliver a broad spectrum of possible utilization methods when structuring liquid fats to solid forms. The review discusses a natural gums&rsquo; structuring and gelling behavior to capture the oil droplets and form the water/oil gelling emulsions basing on their structural conformation, internal charge, and polymeric characteristics. The specific parameters and characteristics of natural gums based oleogels are also discussed. In the future, oleogels may eliminate saturated and trans fats from food products and allow the production of low-fat products, thus reducing the environmental damage caused by the excessive use of palm oil. The increasing knowledge of molecular interaction in polysaccharide chains of natural gums allows to apply more sustainable and wiser strategies towards product formulation. Innovative solutions for using oleogels based on natural polysaccharide biopolymers let incorporate them into the food matrix and replace fats completely or create blends containing the source of fats and the addition of the oleogel. The profound insight into molecular characteristics of natural gums in the function of being oleogelators is presented

Comparison of Conventional and Microwave Assisted Heating on Carbohydrate Content, Antioxidant Capacity and Postprandial Glycemic Response in Oat Meals

Minimally processed cereal breakfast products from whole grain entered the market due to consumer demand of more nutritional food with more controlled sugar release. However, the subsequent processing of such products with different cooking methods in the consumer’s kitchen may lead to significant differentiation of their nutritional value. Therefore, the evaluation of the impact of frequently used cooking methods on a final quality of breakfast cereals meal is needed. The present study investigates how the two different methods of heating, conventional and microwave (MW) assisted, affect the carbohydrate content, profile and resulting glycemic index of so prepared food as well as the antioxidant activity of meals. Two products available on the market—oat bran and flakes—were used. The highest starch content in fluid phase of oatmeal was detected in samples heated for 3 min with microwaves, regardless the type. The lowest starch content was obtained for 5 min MW heated flakes sample. The total content of glucose was about 1.5 times lower in bran vs. flakes oatmeal. The highest β-glucan content in fluid fraction was also observed for bran meal but its release was independent of applied conditions

Use of essential oils against foodborne spoilage yeasts: advantages and drawbacks

The occurrence of spoilage yeasts in foodstuffs can exert detrimental effects on their quality. Recent scientific studies have demonstrated the effective application of essential oils (EOs) as natural preservatives for controlling spoilage yeasts in foods as: fruit and fruit juices, raw vegetables, cereal- based products, meat-based products, and dairy products. Notwithstanding, the main limitation in using EOs, especially when applied at high concentration, is related to their strong impact on the sensory traits of the treated foods. Hence, to preserve food quality and to assure antifungal activity, the optimal formulation, concentration, and combination of each EO should be defined for each specific food matrix. Research in this direction should equally and carefully select the most suitable EO, depending on the sensory quality parameters of the target food

Microwave-Supported Modulation of Functional Characteristics of Gluten-Free Breads

Currently, the market for gluten-free products is experiencing a significant growth due to, mainly, the increase in the number of gluten-intolerant patients diagnosed and to the merging of a new niche market for consumers who optionally avoid gluten. Native flours are perceived as viable alternatives for industrially used starch and hydrocolloids blends, which lack in the vitamins and minerals that are in abundance in non-refined raw materials. This study delves into the potential of microwave technology in enhancing the functional and nutritional attributes of gluten-free breads. The research was conducted by employing 900 W microwave power for 8 min for buckwheat and teff flours modification with an initial moisture content of 30%. The modified flours were blended with rice flour and baked to verify the potential of microwave high moisture treatment for adjusting the texture and nutritional quality of the bread. The results revealed that microwave treatment of flours helped in retaining a higher level of essential nutrients and bioactive compounds in gluten-free breads