Andean purple maize to produce extruded breakfast cereals: impact on techno-functional properties and sensory acceptance.

BACKGROUND: Andean purple maize (APM) is an ancient crop widely used as a natural coloring in traditional Peruvian cuisine. However, it has been little explored within the food industry. The present study assessed how APM impacts on techno-functional properties and sensory acceptance of breakfast cereals. Extruded samples formulated with 100, 75, 50, and 25% APM, and complemented with yellow corn grits (YCG), were analyzed for their techno-functional and sensory properties. RESULTS: Increases in bulk density, as well as reduction in the expantion and porosity were observated for extrudates containing ≥ 50% APM, accompanied by an increase in purple color intensity. Increase in milk absorption index, reduction in milk solubility index and decrease in cereal hardness with increase in APM were also observed. Despite this, APM extented the cereal bowl-life. High sensory scores of overall liking (6) and color (7) were obtained for extruded formulations containing ≥ 50% APM and low values for extrudates with 25% APM. Aroma, flavor, and texture scores did not present significant differences. CONCLUSION: APM is an ingredient with the potential to be used to produce breakfast cereals since it improves their techno-functional characteristics and sensory acceptance, at the same time, it leads to the production of healthy, nutritious, and sustainable food. © 2022 Society of Chemical Industry.

Bound phenolics in foods, a review.

Among phytochemicals, phenolic compounds have been extensively researched due to their diverse health benefits. Phenolic compounds occur mostly as soluble conjugates and insoluble forms, covalently bound to sugar moieties or cell wall structural components. Absorption mechanisms for bound phenolic compounds in the gastrointestinal tract greatly depend on the liberation of sugar moieties. Food processes such as fermentation, malting, thermoplastic extrusion or enzymatic, alkaline and acid hydrolyses occasionally assisted with microwave or ultrasound have potential to release phenolics associated to cell walls. Different kinds of wet chemistry methodologies to release and detect bound phenolic have been developed. These include harsh heat treatments, chemical modifications or biocatalysis. New protocols for processing and determining phenolics in food matrices must be devised in order to release bound phenolics and for quality control in the growing functional food industry.

Características tecnológicas de farinhas de arroz pré-gelatinizadas obtidas por extrusão termoplástica / Technological properties of pre-gelatinized rice flour obtained by thermoplastic extrusion

A farinha de arroz tem sido um ingrediente atrativo para a indústria de extrusados, devido à suas qualidades como sabor suave, cor branca e hipoalergenicidade. Objetivou-se, neste trabalho, produzir e analisar farinha de arroz pré-gelatinizada (FPG) por extrusão termoplástica. As FPG foram produzidas num extrusor termoplástico monorosca Brabender, variando-se a umidade (19,2 a 24,8 por cento) e a temperatura de extrusão (108 a 192ºC). As características de torque, índice de expansão, propriedades viscoamilográficas, índice de absorção em água (IAA) e índice de solubilidade em água (ISA) das FPG foram analisadas por metodologia de superfície de resposta (MRS) e análise de componentes principais (ACP). Os resultados analisados por MRS e ACP indicaram que o torque e o índice de expansão dos extrusados apresentaram os maiores valores quando foram usados os menores teores de umidade. As FPG apresentaram, dentro das propriedades viscoamilográficas, a viscosidade inicial de pasta maior em temperaturas mais altas, já a viscosidade a 95ºC e a 50ºC foram maiores quando temperatura e umidade estavam em extremos opostos. O IAA foi menor quando se usaram baixas temperaturas e maiores teores de umidades; no entanto, o ISA, quando analisado pela MRS, não apresentou influência da temperatura e umidade, mas quando analisado pela ACP, foi maior quando as temperaturas estavam entre 120 - 150ºC e os teores de umidade entre 19,2 e 22 por cento. Concluindo, as análises de MRS e de ACP mostraram que a variação das propriedades tecnológicas das FPG foram relacionadas aos extremos de temperatura e/ou umidade utilizados durante o processo de extrusão, e a ACP foi capaz de complementar a análise feita através da MRS.

The rice flour has become an attractive ingredient in the extrusion industry due to its unique attributes such as bland taste, white color and hypoallergenicity. The purpose of this research was to produce and analyze pre-gelatinized rice flour (GRF) for thermoplastic extrusion. The GRF was extruded using a Brabender single screw extruder, varying moisture (19.2 - 24.8 percent) and extrusion temperature (108 - 192ºC). Torque, expansion index (EI), viscographic properties, water absorption index (WAI), and water solubility index (WSI) characteristics of GRF were analyzed using response surface methodology (RSM) and main component analysis (PCA). The results, analyzed by MRS and PCA, indicated that during the process, the values of torque and EI increased when lower moisture was used. Considering viscographic properties, GRF presented a higher initial viscosity of the starch paste when in higher temperatures, while viscosities at 95ºC and at 50ºC increased when temperature and moisture were at extreme opposites. WAI decreased when lower temperatures and higher moisture were used. WSI was not influenced by temperature and moisture when analyzed using MRS, but with PCA, there was an increase when temperatures ranged between 120 - 150ºC and moisture between 19.2 - 22 percent. In conclusion, both MRS and PCA analysis showed that a variation in the technological properties of GRF were related to the use of opposite extremes of temperature and/or moisture during the extrusion process, and the PCA was able to complete the analysis done using MRS.

Detoxificação de milho (zea mays L.) contaminado com aflatoxinas através do processamento por extrusão termoplástica / Detoxificação de milho (zea mays L.) contaminado com aflatoxinas através do processamento por extrusão termoplástica

Experiments were conducted to study the efficiency of the thermoplastic extrusion process in reducing aflatoxin levels on naturally contaminated yellow dent corn. Quantification was accomplished by high performance liquid chromatography (HPLC). The extration method used was efficient, since recovery of added anatoxins B1, B2, G1 e G2 (10 ppb each) was 104,0; 102,7; 92,5 and 77,0% respectivaly. Subjecting contaminated yellow com flour samples at 35% moisture the thermoplastic extrusion process reduced aflatoxin B1, B2 and G2 levels below the FDA guideline of 20 ppb total aflatoxin.

Foram realizados experimentos com a finalidade de se estudar a detoxificação de milho, naturalmente contaminado com aflatoxinas, através do processamento por extrusão termoplástica. A quantificação foi realizada por Cromatografia Liquida de Alto Desempenho (CLAD). O método de extração utilizado foi bastante eficiente pois apresentou percentuais de recuperação de 104,0; 102,7; 92,5 e 77,0% para as aflatoxinas B1r B2, G1 e G2 respectivamente. O processamento por extrusão termoplástica de farinha de milho a 35% umidade reduziu o teor das aflatoxinas contaminantes da amostra (B1, B2, G2) inferiores aos limites permitidos pela legislação Americana (FDA) que é de 20 ppb.

Detoxificação de milho (zea mays L.) contaminado com aflatoxinas através do processamento por extrusão termoplástica / Detoxificação de milho (zea mays L.) contaminado com aflatoxinas através do processamento por extrusão termoplástica

Experiments were conducted to study the efficiency of the thermoplastic extrusion process in reducing aflatoxin levels on naturally contaminated yellow dent corn. Quantification was accomplished by high performance liquid chromatography (HPLC). The extration method used was efficient, since recovery of added anatoxins B1, B2, G1 e G2 (10 ppb each) was 104,0; 102,7; 92,5 and 77,0% respectivaly. Subjecting contaminated yellow com flour samples at 35% moisture the thermoplastic extrusion process reduced aflatoxin B1, B2 and G2 levels below the FDA guideline of 20 ppb total aflatoxin.  

Foram realizados experimentos com a finalidade de se estudar a detoxificação de milho, naturalmente contaminado com aflatoxinas, através do processamento por extrusão termoplástica. A quantificação foi realizada por Cromatografia Liquida de Alto Desempenho (CLAD). O método de extração utilizado foi bastante eficiente pois apresentou percentuais de recuperação de 104,0; 102,7; 92,5 e 77,0% para as aflatoxinas B1r B2, G1 e G2 respectivamente. O processamento por extrusão termoplástica de farinha de milho a 35% umidade reduziu o teor das aflatoxinas contaminantes da amostra (B1, B2, G2) inferiores aos limites permitidos pela legislação Americana (FDA) que é de 20 ppb.