Tag Archives: extrusion

1425-1434 G. Krumina–Zemture, I. Beitane and I. Cinkmanis
Flavonoids and total phenolic content in extruded buckwheat products with sweet and salty taste
Abstract |

Flavonoids and total phenolic content in extruded buckwheat products with sweet and salty taste

G. Krumina–Zemture¹*, I. Beitane¹ and I. Cinkmanis²

¹Latvia University of Agriculture, Faculty of Food Technology, Department of Nutrition, Riga street 22, LV–3004, Jelgava, Latvia
²Latvia University of Agriculture, Faculty of Food Technology, Department of Chemistry, Liela street 2, LV–3001, Jelgava, Latvia
*Correspondence: gita.krumina@llu.lv

Abstract:

The aim of research was to evaluate the effect of added ingredients used for taste improvement on flavonoids and total phenolic content in extruded buckwheat products. The added ingredients were – sugar, vanilla sugar, stevia, agave syrup, cinnamon, caraway, garlic powder, sweet pepper powder and salt. Six extruded buckwheat products were analysed, where an extruded buckwheat product without added ingredients was a control sample, two extruded buckwheat products were with sweet taste and three products with salty taste. Total phenolic content was determined using the modified Folin–Ciocalteu method but flavonoid content according to LC-TOF-MS method.
The highest total phenolic content (p < 0.05) was determined in extruded buckwheat product with vanilla sugar + stevia (91.17 ± 0.67 GAE mg 100g-1DW). It was almost three times higher than in the control sample. The significant differences were observed in extruded buckwheat products with caraway + salt + agave syrup (41.5 ± 0.12 GAE mg 100g-1DW) and sweet pepper powder + salt + agave syrup (42.39 ± 0.80 GAE mg 100g-1DW) comparing to other extruded products (p < 0.05). The highest content of rutin and quercetin (p < 0.05) was established in extruded buckwheat product with garlic powder + salt + agave syrup, whereas the highest content of catechin and epicatechin – in extruded buckwheat product with vanilla sugar + stevia. The extruded buckwheat product with caraway + salt + agave syrup in addition contained luteolin, kaempferol and isoquercitrin. The results of research showed that some added ingredients used for taste improvement can significantly influence the total phenolic content and flavonoid content.

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1331-1340 I. Beitane, G. Krumina–Zemture and M. Sabovics
Effect of germination and extrusion on the phenolic content and antioxidant activity of raw buckwheat (Fagopyrum esculentum Moench)
Abstract |
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Effect of germination and extrusion on the phenolic content and antioxidant activity of raw buckwheat (Fagopyrum esculentum Moench)

I. Beitane¹*, G. Krumina–Zemture¹ and M. Sabovics²

¹Latvia University of Agriculture, Faculty of Food Technology, Department of Nutrition, Riga Street 22, LV–3004 Jelgava, Latvia
²Latvia University of Agriculture, Faculty of Food Technology, Department of Food Technology, Riga street 22, LV–3004 Jelgava, Latvia
*Correspondence: ilze.beitane@llu.lv

Abstract:

The aim of the research was to determine the total phenolic content, antioxidant activity and phenolic compounds in raw and germinated common buckwheat grain and their extruded products in order to estimate the effect of germination and extrusion on the total phenolic content, antioxidant activity and phenolic compounds in buckwheat. A total of 10 buckwheat samples were analysed, where the raw buckwheat grain was the control sample, four samples were germinated and then extruded. The total phenolic content was determined using the Folin–Ciocalteu assay. The antioxidant activity was determined using a micro plate assay and phenolic compounds with Liquid Chromatography –Time of Flight Mass Spectrometer method.
The results showed that germination of buckwheat significantly affected the total phenolic content, antioxidant activity, radical scavenging activity and content of phenolic compounds. The decrease of the total phenolic content, antioxidant activity, radical scavenging activity and the content of some phenolic compounds depended on germination time – 48 h of germination provided greater concentrations at the end of a 24 h germination period, whereas the content of some phenolic compounds like rutin, quercetin and vitexin increased substantially after germination, besides, the increase of phenolic compounds depended on the germination time. In total 26 different phenolic compounds were detected in raw and germinated buckwheat samples and only one compound with an m/z value 385.1282 was unidentified. The data of extrusion revealed a significant decrease of total phenolic content, antioxidant activity, radical scavenging activity and phenolic compounds content in buckwheat samples (P < 0.05). In the extruded buckwheat samples novel phenolic compounds like 4–hydroxybenzoic acid, homovanillic acid, catechin, ferulic acid, and hyperoside were detected.

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