Effect of extrusion cooking process parameters on the retention of bilberry anthocyanins in starch based food

Understanding the physical breakdown and catechin bioaccessibility of third generation extruded snacks enriched with catechin using the human gastric simulator

The nutritional quality of third-generation snacks prepared from rice flour by extrusion can be improved by the addition of polyphenols such as catechins, which are known to be more stable at high temperatures. However, the extrusion parameters can impact the breakdown and release of bioactive compounds and decrease the catechin bioaccessibility. Accordingly, this study investigated the impact of different extrusion parameters, including different extrusion temperatures (110, 135, and 150 °C) and moisture content prior to extrusion (27 and 31%), on the breakdown and bioaccessibility of catechin-enriched snacks during in vitro dynamic digestion using the Human Gastric Simulator (HGS). The extrusion parameters did not significantly impact most measured variables by themselves, indicating that within the tested ranges, any of the processing conditions could be used to produce a product with similar digestive behavior. However, the interaction of extrusion parameters (temperature and moisture content) played a significant role in the snack behavior during digestion. For example, the combination of 27% moisture content and 150 °C extrusion temperature had higher catechin bioaccessibility and higher starch hydrolysis than the other treatments. Overall, these findings suggest that the processing conditions of third generation snacks enriched with catechin can be optimized within certain ranges with limited modifications in the digestive properties.

Bacterial Volatiles Known to Inhibit Phytophthora infestans Are Emitted on Potato Leaves by Pseudomonas Strains

Bacterial volatiles play important roles in mediating beneficial interactions between plants and their associated microbiota. Despite their relevance, bacterial volatiles are mostly studied under laboratory conditions, although these strongly differ from the natural environment bacteria encounter when colonizing plant roots or shoots. In this work, we ask the question whether plant-associated bacteria also emit bioactive volatiles when growing on plant leaves rather than on artificial media. Using four potato-associated Pseudomonas, we demonstrate that potato leaves offer sufficient nutrients for the four strains to grow and emit volatiles, among which 1-undecene and Sulfur compounds have previously demonstrated the ability to inhibit the development of the oomycete Phytophthora infestans, the causative agent of potato late blight. Our results bring the proof of concept that bacterial volatiles with known plant health-promoting properties can be emitted on the surface of leaves and warrant further studies to test the bacterial emission of bioactive volatiles in greenhouse and field-grown plants.

Changes in Phenolics during Cooking Extrusion: A Review

In this paper, significant attention is paid to the retention of phenolics in extrudates and their health effects. Due to the large number of recent articles devoted to total phenolic content (TPC) of input mixtures and extrudates, the technological changes are only presented for basic raw materials and the originating extrudates, and only the composites identified has having the highest amounts of TPC are referred to. The paper is also devoted to the changes in individual phenolics during extrusion (phenolic acids, flavonoids, flavonols, proanthocyanidins, flavanones, flavones, isoflavons, and 3-deoxyanthocyanidins). These changes are related to the choice or raw materials, the configuration of the extruder, and the setting the technological parameters. The results found in this study, presented in the form of tables, also indicate whether a single-screw or twin-screw extruder was used for the experiments. To design an extrusion process, other physico-chemical changes in the input material must also be taken into account, such as gelatinization of starch; denaturation of protein and formation of starch, lipids, and protein complexes; formation of soluble dietary fiber; destruction of antinutritional factors and contaminating microorganisms; and lipid oxidation reduction. The chemical changes also include starch depolymerization, the Maillard reaction, and decomposition of vitamins.

Properties of Extruded Snacks Prepared from Corn and Carrot Powder with Ascorbic Acid Addition

The objective of this research was to investigate the potentiality of carrot powder (CP) utilization at levels 4, 6, or 8% as ingredient of corn snacks and evaluation of the extrusion influence on functionally important ingredients such as carotenoids (color), polyphenols, fiber, fat, and antioxidant activity. The influence of ascorbic acid (AA) as an external source at levels 0.5 and 1% on this particular extrusion was also investigated. A single-screw extruder at two temperature regimes (135/170/170 °C (E1) and 100/150/150 °C (E2)) carried out extrusion. The E1 temperature regime acted favorably on total polyphenol content and crude fiber, but fat preferred the E2 regime. Extrusion, especially the E1 temperature regime, increased the extractability of carotenoids. Ascorbic acid degraded during extrusion, but it still provided protection to carotenoids and color attributes of extrudates. Snacks with increased nutritional and functional value due to carrot powder addition were successfully produced, which is a starting point for production of a new type of extruded snacks.

Influence of extrusion cooking on phytochemical, physical and sorption isotherm properties of rice extrudate infused with microencapsulated anthocyanin

The effect of extrusion cooking on the quality of rice extrudate with infused microencapsulated anthocyanin was investigated. The moisture sorption isotherm of the extrudate was also studied. The rotatable central composite design was used to optimize the extrusion process and the optimized conditions were: screw speed, 121 rpm; barrel temperature, 91.89 °C; and moisture content, 22.03%. The extrudate showed anthocyanin content of 0.218 mg/L; true density, 1.48 g/cc; water activity 0.51, water solubility index, 7.49%; and specific mechanical energy, 31.39 kJ/kg. The antioxidant activity and solubility of the extrudate were higher as compared with native extrudate. The moisture sorption isotherm of the extrudate was found to follow type III isotherm behavior according to the Brunauer-Emmett-Teller classification. The sorption isotherm was analyzed using several models and the Caurie and Peleg models were best fitted with the extrudate isotherm data. The present work manifested a way to develop antioxidant rich extrudate.

Application of extrusion technology in plant food processing byproducts: An overview

The food processing industry generates an immense amount of waste, which leads to major concerns for its environmental impact. However, most of these wastes, such as plant-derived byproducts, are still nutritionally adequate for use in food manufacturing. Extrusion is one of the most versatile and commercially successful processing technologies, with its widespread applications in the production of pasta, snacks, crackers, and meat analogues. It allows a high degree of user control over the processing parameters that significantly alters the quality of final products. This review features the past research on manufacture of extruded foods with integration of various plant food processing byproducts. The impact of extrusion parameters and adding various byproducts on the nutritional, physicochemical, sensory, and microbiological properties of food products are comprehensively discussed. This paper also provides fundamental knowledge and practical techniques for food manufacturers and researchers on the extrusion processing of plant food byproducts, which may increase economical return to the industry and reduce the environmental impact.

Consumer acceptance and sensory drivers of liking for high plant protein snacks

BACKGROUND

Consumers are being encouraged to increase the proportion of plant protein in their diet to tend to a sustainable food system. Solutions could include developing a food rich in plant protein. However, these new products have an interest only if they are in accordance with expectation and the liking of consumers. In this context, extruded snack balls were developed to explore the sensory drivers of liking and barriers to consumption of formulated products with a high level of plant proteins. Eight different products varying in the type of cereal flour (rice or wheat) and pea flour content (from 60% to 90%) were developed following a factorial design. Eighty omnivore and 72 flexitarian consumers were recruited to evaluate the liking of these products. In addition, their sensory properties were described by a trained panel according to a profile method.

RESULTS

The cereal type had globally more influence on liking than the percentage of pea. However, liking was inversely correlated with pea flour content, regardless of the cereal type. The main drivers of liking are texture criteria (in particular crispy and puffy), whereas flavor perception (pea, green) constitutes a barrier to acceptance. Interestingly, very few differences of liking were observed depending on the diet of consumers even though the attitudes of flexitarian'towards such type of products differed from those of omnivores. We identified three clusters of consumers based on their preferences. Pea flavor acceptance or rejection could explain these clusters. Although most consumers rejected pea flavor, approximately 40% of the participants preferred the products with highest pea content.

CONCLUSION

The results of the present study will help provide guidance for innovative plant food design and formulation. © 2019 Society of Chemical Industry.

Extrusion of a Curcuminoid-Enriched Oat Fiber-Corn-Based Snack Product

Extruded snack products were made from an oat fiber-corn flour matrix fortified with 1.5% (w/w) curcuminoids (750 mg curcuminoids/100 g) to improve the solubility and stability of curcuminoids. The effects of extruder feed moisture content (21%, 28%, and 35%) and screw speed (200 and 300 rpm) on the extrusion parameters and physical properties of final snacks were investigated. Curcuminoids lost during extrusion and curcuminoids loss during subsequent drying of extrudates were analyzed, to separate the losses occurring in each unit process. Drying post extrusion (at 50 °C for 4 hr) was essential to obtain a crunchy shelf stable product (5% moisture). Curcuminoids loss during extrusion was from 17% to 84%, with high loss for the extrusion with low feed moisture content (21%). A further curcuminoids loss of 4% to 44% occurred during drying, with much higher loss for the extrudate with high moisture content. Total curcuminoids retained after extrusion and drying was 12% to 41% (59% to 88% loss), equivalent to 180 to 616 mg curcuminoids retained per 100 g snack, levels within recommended daily dose. Curcuminoids retained after drying was stable during 80 days of storage at 25 °C. The results highlighted the importance of understanding the impact of each unit process separately (for example, extrusion and drying) on the stability of curcuminoids for the development of healthier extruded snacks. PRACTICAL APPLICATION: Extruded snacks products were developed by fortifying the snacks with oat fiber and curcuminoids in order to address the need for a healthy ready to eat food products. Some extrusion characteristics were selected to produce snack products which have favorable properties in terms of consumer acceptance.

Extrusion of apple pomace increases antioxidant activity upon in vitro digestion

Apple pomace, a by-product of juice production, is a high-fibre, high-polyphenol functional food ingredient.

Effect of extrusion conditions on the physicochemical and phytochemical properties of red rice and passion fruit powder based extrudates

The passion fruit powder blended rice flour based extrudate was developed and investigated in terms of physicochemical and phytochemical properties. The extrusion process was performed using a twin screw extruder and optimized using rotatable central composite design followed by response surface methodology. The effect of process parameters such as temperature (80-150 °C), screw speed (200-400 rpm), moisture content (20-30%) and passion fruit powder (0-15%) on product quality was investigated. The optimum extrusion conditions of temperature, screw speed, feed moisture content, and passion fruit powder were 97.50 °C, 250 rpm, 25.20% and 11.25%, respectively. At optimum condition, the predicted values of responses were expansion ratio 8.05, water absorption index 2.77, total phenolic content 129.492 mg GAE/100 g and DPPH scavenging activity 65.79%. A comparison between optimized and control extrudates revealed that thermal, crystallinity and morphological properties of extrudates differed significantly. The comparison was also conducted in terms of FT-IR, SEM-EDS and HPLC analysis. The phytochemical properties showed that β-carotene, cyanidin-3-glucoside, peonidin-3-D-glucoside chloride were higher in control whereas the optimized sample evinced more (±)-α-tocopherol and D-α-tocopherol.

Use of Red Cactus Pear (Opuntia ficus-indica) Encapsulated Powder to Pigment Extruded Cereal

Encapsulated powder of the red cactus pear is a potential natural dye for the food industry and a known antioxidant. Although the use of this powder is possible, it is not clear how it alters food properties, thus ensuing commercial acceptability. The aim of this study was to evaluate the effect of encapsulated powder of the red cactus pear on the physicochemical properties of extruded cereals. The powder was mixed (2.5, 5.0, and 7.5% w/w) with maize grits and extruded (mix moisture 22%, temperature 100°C, and screw speed 325 rpm). The physical, chemical, and sensory characteristics of the extruded cereal were evaluated; extruded cereal without encapsulated powder was used as a control. All cereal extrudates pigmented with the encapsulated powder showed statistically significant differences (P<0.05) in expansion, water absorption, color, density, and texture compared to the control. The encapsulated powder had a positive effect on expansion and water absorption indices, as well as color parameters, but a negative effect on density and texture. Extruded cereal properties were significantly (P<0.05) correlated. Sensorially, consumers accepted the extruded cereal with a lower red cactus pear powder content (2.5% w/w), because this presented characteristics similar to extruded cereal lacking pigment.

Stability and bioaccessibility of anthocyanins in bakery products enriched with anthocyanins

Anthocyanins, water soluble polyphenols, have been associated with several beneficial health effects.

Effect of extrusion cooking on bioactive compounds in encapsulated red cactus pear powder

Red cactus pear has significant antioxidant activity and potential as a colorant in food, due to the presence of betalains. However, the betalains are highly thermolabile, and their application in thermal process, as extrusion cooking, should be evaluated. The aim of this study was to evaluate the effect of extrusion conditions on the chemical components of red cactus pear encapsulated powder. Cornstarch and encapsulated powder (2.5% w/w) were mixed and processed by extrusion at different barrel temperatures (80, 100, 120, 140 °C) and screw speeds (225, 275, 325 rpm) using a twin-screw extruder. Mean residence time (trm), color (L*, a*, b*), antioxidant activity, total polyphenol, betacyanin, and betaxanthin contents were determined on extrudates, and pigment degradation reaction rate constants (k) and activation energies (Ea) were calculated. Increases in barrel temperature and screw speed decreased the trm, and this was associated with better retentions of antioxidant activity, total polyphenol, betalain contents. The betacyanins k values ranged the -0.0188 to -0.0206/s and for betaxanthins ranged of -0.0122 to -0.0167/s, while Ea values were 1.5888 to 6.1815 kJ/mol, respectively. The bioactive compounds retention suggests that encapsulated powder can be used as pigments and to provide antioxidant properties to extruded products.

Effect of different calcium sources on the bioactive compounds stability of extruded and nixtamalized blue maize flours

The stability of antioxidants in extruded and nixtamalized blue maize flours with calcium hydroxide [Ca(OH)2] and calcium lactate [C6H10O6Ca] were evaluated. Extruded blue maize flours batches were obtained by mixing blue maize flours separately with different Ca(OH)2 (0.1, 0.2 and 0.3 %) and C6H10O6Ca (0.3, 0.6 and 0.9 %) concentrations respectively and extruded to obtain the extruded flours. For nixtamalized flours, the maize grains were cooked at 1 % Ca(OH)2 and 2.95 % C6H10O6Ca concentrations respectively. Color, antioxidant activity, total phenolics, total anthocyanins and individual anthocyanins, contents were analyzed. Color, antioxidant activity, anthocyanins contents and total phenolics decreased as the calcium hydroxide concentration increased. In contrast, increasing the calcium lactate concentration on the extruded flours had the opposite effect. The extrusion process retained 57-47 %, 72-62 % and 79-65 % of the anthocyanins content, total phenolic content and antioxidant activity, respectively. These retention rates were higher than those of the nixtamalized flours using the same calcium sources. Cyanidin-3-glucoside and pelargonidin-3-glucoside were identified in the maize kernel and flours. Cyanidin-3-glucoside concentration was increased by both extrusion and nixtamalization processed with either of the two calcium sources. In contrast, pelargonidin-3-glucoside concentration decreased by both processes. Other anthocyanins were observed, but they were not identified.