Changes in Nutritional Properties and Bioactive Compounds in Cereals During Extrusion Cooking

Maintaining and improving the nutritional quality of foods during processing are the main market and industry concerns. Thus, research should focus on novel and sustainable ways for selecting the appropriate processing method that either increases or does not affect the nutrient content of foods. Thermal processing techniques such as extrusion cooking are widely used for producing breakfast cereals, snack foods, pasta, pet food, etc. Extrusion cooking is a continuous process that uses a combination of high-temperature, high-pressure, and high shear conditions in a short period of time, which results in molecular transformation and chemical reactions within the extruded products. Extrusion cooking brings on many biochemical changes such as denaturation of proteins, gelatinization of starch, lipid modifications, inactivation of microorganisms and enzymes, formation of volatile flavor components, and increase in soluble dietary fiber. Furthermore, extrusion cooking has the potential to improve the nutritional quality of the products by improving starch and protein digestibility and increasing the retention of bioactive compounds with antioxidant properties. Also, this highly efficient technology minimizes water pollution and energy consumption. This review aims to discuss the current information regarding changes in nutritional properties and bioactive compounds in cereals processed by extrusion cooking

Characterization of Peptides Found in Unprocessed and Extruded Amaranth (Amaranthus hypochondriacus) Pepsin/Pancreatin Hydrolysates

The objectives of this study were to characterize peptides found in unprocessed amaranth hydrolysates (UAH) and extruded amaranth hydrolysates (EAH) and to determine the effect of the hydrolysis time on the profile of peptides produced. Amaranth grain was extruded in a single screw extruder at 125 °C of extrusion temperature and 130 rpm of screw speed. Unprocessed and extruded amaranth flour were hydrolyzed with pepsin/pancreatin enzymes following a kinetic at 10, 25, 60, 90, 120 and 180 min for each enzyme. After 180 min of pepsin hydrolysis, aliquots were taken at each time during pancreatin hydrolysis to characterize the hydrolysates by MALDI-TOF/MS-MS. Molecular masses (MM) (527, 567, 802, 984, 1295, 1545, 2034 and 2064 Da) of peptides appeared consistently during hydrolysis, showing high intensity at 10 min (2064 Da), 120 min (802 Da) and 180 min (567 Da) in UAH. EAH showed high intensity at 10 min (2034 Da) and 120 min (984, 1295 and 1545 Da). Extrusion produced more peptides with MM lower than 1000 Da immediately after 10 min of hydrolysis. Hydrolysis time impacted on the peptide profile, as longer the time lower the MM in both amaranth hydrolysates. Sequences obtained were analyzed for their biological activity at BIOPEP, showing important inhibitory activities related to chronic diseases. These peptides could be used as a food ingredient/supplement in a healthy diet to prevent the risk to develop chronic diseases

Improving Polyphenolic Compounds: Antioxidant Activity in Chickpea Sprouts through Elicitation with Hydrogen Peroxide

Elicitation appears to be a promising alternative to enhance the bioactive compound content and biological activities of legume sprouts. Multi-response optimization by response surface methodology (RSM) with desirability function (DF) was used to optimize the elicitor concentration (hydrogen peroxide (H2O2)) and germination time in order to maximize total phenolic content (TPC), total flavonoids content (TFC), and antioxidant activity (AOX) of chickpea sprouts. Chemical, antinutritional, and nutraceutical properties of optimized chickpea sprouts (OCS) were also determined. The predicted regression models developed were efficiently fitted to the experimental data. The results of the desirability function revealed that optimum attributes in chickpea sprouts can be achieved by the application of 30 mM H2O2 and 72 h of germination time, with global desirability value D = 0.893. These OCS had higher (p < 0.05) TPC (7.4%), total iso-flavonoids (16.5%), AOX (14.8%), and lower phytic acid (16.1%) and saponins (21.8%) compared to H2O2 non-treated chickpea sprouts. Optimized germination conditions slightly modified the flavonoid profile in chickpea; eight iso-flavonoids were identified in OCS, including formononetin and biochanin A, which were identified as the major compounds. Results from this study support elicitation with H2O2 as an effective approach to improve phytochemical content and antioxidant activity in chickpea sprouts

Nutritional and antioxidant potential of a desert underutilized legume – tepary bean (Phaseolus acutifolius). Optimization of germination bioprocess

Abstract Tepary bean (Phaseolus acutifolius) is a short life cycle legume, resistant to many diseases and drought, originally from the deserts and semi-arid environment of Northwestern Mexico and the Southwestern US. Its mature seeds are scarce consumed, and their high protein and carbohydrate contents are underutilized. The aim was to identify optimal germination conditions for producing a functional flour with máximum values of protein content (PC), antioxidant activity (AoxA), and total phenolic content (TPC). A central composite rotatable experimental design with two factors [Germination temperature (GT, 20-40 ºC)/Germination time (Gt, 10-170 h)] in five levels was used (13 treatments). Optimized conditions of germination to obtain a functional tepary bean flour were GT= 32 °C/Gt=120 h. Germination was an effective strategy to increase PC (+57.5%), AoxA (+188-318%), TPC (+232%), flavonoid content (+114), and dietary fiber (+246%) in tepary bean seeds. Therefore, the optimized germinated tepary bean flour could be used as a source of natural antioxidants, protein, and dietary fiber in the formulation of functional foods

Antioxidant and Antimutagenic Activities of Optimized Extruded Desi Chickpea (Cicer arietinum L) Flours

The objective of this study was to evaluate the effect of optimized extrusion cooking process on antioxidant and antimutagenic properties of desi chickpea cultivars. Three desi chickpea cultivars (Brown-ICC3512, Red-ICC13124, Black-ICC3761) were studied. Extrusion was carried out in a single-screw extruder; the operation conditions were previously optimized to obtain maximum antioxidant activity in extruded chickpea flour: Extrusion temperature (ET) = 155°C, and screw speed (SS) = 240 rpm. The antioxidant activity (AOA) was evaluated using the oxygen radical absorbance capacity (ORAC) assay. Antimutagenic activity (AMA) of ground samples extracts was tested against 1-Nitropyrene (1-NP) with the Kado microsuspension assay using Salmonella typhimurium strain TA98. The total phenolic (TPC) and flavonoid (TFC) contents, AOA, and AMA of raw desi chickpea cultivars ranged from 1.31 to 1.35 mg GAE g-1 sample, dw, from 0.464 to 1.006 mg CAE g-1 sample, dw, from 54.9 to 57.3 mmol TE g-1 sample, dw, and from 57.8-62.3% inhibition, respectively. Brown-ICC3512 showed the highest TFC and AOA, while Red-ICC13124 had the highest AMA. The extrusion cooking process increased the TPC, AOA and AMA of whole desi chickpea grains in 5.3-9.2%, 9.9-12.2%, and 17.5-21.9%, respectively. The optimized extrusion cooking process is a recommended technology for increasing AOA and AMA in desi chickpea grains, which could be used as functional foods