Agnieszka Wójtowicz

Influence of extrusion-cooking parameters on some quality aspects of precooked pasta-like products.

The present article aims to evaluate some quality parameters and texture characteristics of precooked wheat pasta-like products. Using the methods for pasta and instant noodles the tested parameters were water absorption, starch gelatinization degree, cooking losses, and hardness. The texture profile was characterized using Zwick apparatus by cutting test with the head speed of 10 mm/min and expressed as hardness and firmness of hydrated products. SEM pictures were used to illustrate the internal structure of dry and cooked pasta-like products. Dough moisture content and process conditions influenced all tested quality parameters of the pasta-like products processed on a modified single screw extrusion-cooker TS-45 with L: D = 16: 1. Good organoleptical quality (notes higher than 4 in a 5-point scale) and firm texture were observed for common wheat flour pasta processed at 30% m.c. Hardness and firmness of hydrated products lowered with a longer hydration time in hot water. The firmest texture and low stickiness was observed for products with a highest starch gelatinization degree.

Influence of Buckwheat Addition on Physical Properties, Texture and Sensory Characteristics of Extruded Corn Snacks

Abstract The influence of buckwheat addition on physical properties, texture, colour and sensory characteristics of extruded corn snacks are presented in this paper. Snacks were prepared with a single screw extrusion-cooker TS-45 with L:D=12:1, shaped on the circular open die 3 mm, screw speed during processing was set to 120 rpm. Buckwheat flour was added in the amount from 10 to 50% of corn grits mass. Selected physical properties, cutting force and texture with Kramer cell were evaluated. The sensory characteristics and acceptability of buckwheat enriched snacks were evaluated. The expansion ratio lowered, whilst bulk density and durability increased with a higher level of buckwheat addition. Fracturability and hardness lowered with higher buckwheat amount in the recipe. Colour measurements showed lower L* and higher b* values with higher buckwheat addition. Higher buckwheat amount influenced lower sensory notes of snacks.

Gluten-Free Precooked Rice-Yellow Pea Pasta: Effect of Extrusion-Cooking Conditions on Phenolic Acids Composition, Selected Properties and Microstructure.

Rice/yellow pea flour blend (2/1 ratio) was used to produce gluten-free precooked pasta using a single-screw modified extrusion-cooker TS-45. The effect of moisture content (28%, 30%, and 32%) and screw speed (60, 80, and 100 rpm) on some quality parameters was assessed. The phenolic acids profile and selected pasta properties were tested, like pasting properties, water absorption capacity, cooking loss, texture characteristics, microstructure, and sensory overall acceptability. Results indicated that dough moisture content influenced all tested quality parameters of precooked pasta except firmness. Screw speed showed an effect only on some quality parameters. The extrusion-cooking process at 30% of dough moisture with 80 rpm is appropriate to obtain rice-yellow pea precooked pasta with high content of phenolics and adequate quality. These pasta products exhibited firm texture, low stickiness, and regular and compact interne structure confirmed by high score in sensory overall acceptability.

Extruded corn gruels containing linden flowers: quantitation of phenolic compounds and selected quality characteristics

Abstract Extrusion-cooking of plant materials may enhance antioxidant activity and improve health benefits. Selected antioxidant polyphenols in extruded corn gruels enriched with different amounts of linden flowers were determined by LC-ESI-MS/MS and quality characteristics were determined. Phenolic content increased with Tiliae inflorescentia addition and was not decreased by high-temperature extrusion. Linden flower incorporation into instant gruels should be limited to 10% to retain acceptable sensory properties. Graphical Abstract

Radical scavenging activity of extruded corn gruels with addition of linden inflorescence

Abstract Antioxidant activity is one of the most desirable properties of natural compounds. Among these substances are phenolic compounds which exhibit excellent antiradical activity. The main aim of the present study was determination of the free radical scavenging activity of gruels with 5, 10 and 20% addition of linden inflorescence. The studies were based on two methods: TLC-bioautographic assay and spectrophotometric analysis using DPPH (2,2-diphenyl-1-picrylhydrazyl radical). The obtained results indicate that the radical scavenging properties of the extracts are positively correlated with the content of phenolic compounds in gruels and that a high-temperature extrusion process does not deactivate antioxidant polyphenolic compounds. Graphical Abstract

Effect of wheat bran addition and screw speed on microstructure and textural characteristics of common wheat precooked pasta-like products.

Effect of Wheat Bran Addition and Screw Speed on Microstructure and Textural Characteristics of Common Wheat Precooked Pasta-Like Products. The present paper describes the wheat bran addition on microstructure, texture, colour and sensory characteristics of enriched precooked pasta-like products. Precooked pasta-like products were processed on a single screw extrusion-cooker TS-45 with L:D=16:1, shaped on the circular open die. Screw speed during the extrusion-cooking ranged from 60 to 120 rpm. Wheat bran were added in the amount from 5 to 25% of common wheat flour mass. The microstructure showed unmodified bran fractions at low screw speed, in turn higher rpm disrupted wheat bran cell walls. Hardness of dry pasta-like products, evaluated with the cutting test, was diminishing with a higher bran content in the recipe and was increasing with rpm applied. The firmness of hydrated products was decreasing with increasing bran addition (20 and 25% of bran in the recipe), whilst processing at low rpm caused poor quality of pasta-like products with great adhesiveness and stickiness. The higher bran content affected also the lower sensory notes. Colour measurement showed lower L* values for both raw and hydrated products with higher bran addition.

Radical Scavenging Activity of Instant Grits with Addition of Chamomile Flowers Determined by TLC–DPPH• Test and by Spectrophotometric Method

Phenolic compounds possess multiple biological effects, including antioxidant activity. They may act as scavenger of free radicals or prevent their formation. The antioxidant properties of extruded grits enriched with 5%, 10%, and 20% addition of chamomile were evaluated. In order to determine antioxidant activity of samples, TLC–DPPH• test and spectrophotometric method, using DPPH (2,2′-diphenyl-1-picrylhydrazyl radical), were performed. The results of TLC–DPPH• test and spectrophotometric analysis indicated that antioxidant potential of corn grit increased with the addition of Matricaria chamomilla. The study findings confirmed that high-temperature extrusion process has no negative influence on antioxidant activity of polyphenolic compounds, which are present both in the raw and enriched with the Matricaria chamomilla final product.

Active polyphenolic compounds, nutrient contents and antioxidant capacity of extruded fish feed containing purple coneflower (Echinacea purpurea (L.) Moench.)

The growth of fish is directly dependent on feed composition and quality. Medicinal plants can be added to fish feed as adjuvant therapy for the prevention of fish diseases. The purple coneflower (Echinacea purpurea (L.) Moench.) has been reported to have multiple biological effects, including immunomodulatory and antioxidant activity. The most active compounds of E. purpurea are polyphenols - caffeic acid derivatives: caftaric acid, chlorogenic acid, cynarin, echinacoside and cichoric acid. Due to a relatively limited number of studies on the use of the purple coneflower as a nutritional supplement for fish feeding, extruded fish feed with addition of Echinacea roots was produced. In the feed total phenolic content, selected polyphenol contents, the energetic value, nutrient contents and antioxidant capacity were examined. The results indicate that fish feed with addition of the Echinacea has a great potential to be a good source of natural radical scavengers, for example polyphenols, and nutritive ingredients. Antioxidant properties of feed were well correlated with the coneflower content. The study findings confirmed that high-temperature extrusion-cooking process does not deactivate phenolic antioxidant compounds, which are present both in the Echinacea roots and in the final product. Fish feed with addition of E. purpurea can be used as a nutritional supplement in the prevention of fish diseases caused by oxidative stress.

A STUDY OF THE SOLUBILITY OF BIODEGRADABLE FOAMS OF THERMOPLASTIC STARCH

The paper presents the results of a study on the water absorption capacity and solubility of biodegradable starch foams produced with single-screw extruder TS-45 with L/D=12. Two different moulding dies were used: one with a circular hole with the diameter of 3 mm and one with a ring hole with the inner diameter of 5 mm. During the extrusion process, the temperature of the cylinder ranged from 80 to 130°C and the screw speeds applied were: 100 and 130 rpm. For the application of the ring die, it was observed that regardless of the speed of the screw, the use of the raw material of higher moisture content led to the production of materials with higher solubility. As a result, the obtained materials revealed solubility at a level of 40%. The results demonstrate good solubility of the starchy fillers of the packaging, which may indicate their susceptibility to decomposition in the conditions of high ambient humidity. A statistical analysis showed a significant impact of moisture of the raw material on the WSI of starch foams used irrespective of the other parameters of the extrusion-cooking process. The raw material moisture had a significant effect on the water absorption capacity of only TPS foams produced in the ring die at the screw speed of 100 rpm.

Phenolic Acid Content and Antioxidant Properties of Extruded Corn Snacks Enriched with Kale

Prohealth food contains specific components which have positive influence on the health and well-being of the consumer. An important position among bioactive compounds occurs for polyphenols. Many results have indicated that an increased intake of phenolic compounds may reduce the risk of cardiovascular diseases and type 2 diabetes. The objective of the study was production of extruded corn snacks with addition (0, 2, 4, 6, and 8%) of kale (Brassica oleracea L. var. sabellica)—a polyphenol-rich plant. Afterwards, high-performance liquid chromatography-mass spectrometry (LC-ESI-MS/MS) and antioxidant activity analyses of snack extracts were performed. In the corn snacks enriched with kale, fifteen phenolic acids were indicated. These were protocatechuic, 4-OH-benzoic, vanillic, trans-caffeic, cis-caffeic, trans-p-coumaric, cis-p-coumaric, trans-ferulic, cis-ferulic, salicylic, gentisic, syringic, 3-OH-cinnamic, trans-sinapic, and cis-sinapic acids. Both the qualitative and quantitative content of polyphenols increased with the addition of B. oleracea. Data from spectrophotometric analyses of the samples showed high DPPH radical scavenging potential of snacks enriched with 4, 6, and 8% of kale. Snacks enriched with kale contain high level of phenolic acids and, therefore, have great potential to make a valuable source of natural antioxidants. High-temperature short-time extrusion-cooking process had no negative impact on polyphenols activity.