Influence of dried Hokkaido pumpkin and ascorbic acid addition on chemical properties and colour of corn extrudates

Effect of extrusion process conditions on extrudates enriched with carotenoids encapsulated by different methods using gum arabic and vegetable fat as carriers

Bioactive compounds into extruded foods enhance their nutritional value but they are heat and shear labile and prone to oxidation. This study was aimed to examine the impacts of distinct encapsulation methods on the stability of carotenoids under typical extrusion conditions. The study presents innovative encapsulation methods and investigates the protection efficacy of carotenoids degradation, as well as the effects on the physicochemical characteristics of carotenoid-rich products. Thus, spray drying, spray chilling, and their combination were compared based on their ability to protect carotenoids. Processing temperatures were 110 °C and 140 °C, and shear rates 500 and 2000 1/s. Carotenoid retention was determined, β- and α-carotene retention ranged from 17 to 44 % and 18 to 48 %, respectively. Upon storage at room temperature, the carotenoid content was stable for 15 days, followed by a marked reduction after 30 days. Extrudates enriched microparticles produced by spray chilling and the combined methods exhibited higher carotenoid protection during storage. They also showed better quality attributes, notably bulk density, high water absorption index, color properties, and carotenoid retention. These findings suggest that encapsulation can protect carotenoids during extrusion, and the protection can be tailored to optimize the attributes of the final products.

Optimization of the extrusion parameters for the production of lentil-quinoa extrudates enriched with pumpkin

This study aimed to develop a protein-fiber-rich extruded product based on yellow lentil, quinoa, and pumpkin flours. The final product quality is affected by formulation and extrusion parameters. Therefore, the effect of the pumpkin-flour ratio (A: 25-75%) and feed moisture content (C: 14-22%) besides barrel screw speed (B: 120-180 rpm) on the physical attributes of extrudates was investigated. Box-Behnken experimental design and stepwise-response surface method were used to analyze the effects of various process variables and ingredients on extrudates. The pumpkin-flour ratio had a significant positive correlation with bulk density (BD), water solubility index (WSI), and oil absorption index. Whereas the correlation between pumpkin-flour ratio with hardness, porosity, expansion ratio (ER), and water absorption index (WAI) was negative (P < 0.05). The feed moisture content positively affected the water activity (aw) and WAI and negatively affected the harness of samples (P < 0.05). The screw speed had a positive effect on ER, porosity, and WSI, whereas it negatively influenced the hardness, BD, and aw. By increasing the pumpkin-flour ratio, air cell size and wall thickness of samples had been decreased. The results showed that 44.2% pumpkin flour, 22% feed moisture, and 172.1 rpm screw speed gave an optimized product. There was no significant difference between predicted and experimental values (except for ER). The optimized snack was a good source of fiber (around 15%), protein (17.3%), and antioxidants (TPC = 15.28 mg GAE.g-1 and antiradical scavenging activity (DPPH) = 33.66%). The caloric value of the optimized snack was 362.6 cal.100g-1. The current formulation can be considered as the base of snack food or plant-based meat alternatives.

Nutritionally Valuable Components and Heat-Induced Contaminants in Extruded Snack Products Enriched with Defatted Press Cakes

This research studies the influence of the addition of defatted press cakes (from the production of hazelnut, camelina, pumpkin, and hemp seed oil) on nutritionally important components: fibre, resistant starch, polyphenols, hydroxymethylfurfural (HMF), and acrylamide in directly and indirectly expanded snacks. The amounts of press cakes added to corn grits were 3, 6, and 9%. Extrusion was carried out in a laboratory single-screw extruder. For indirectly expanded products (SCFX), supercritical CO2 was injected during extrusion, and secondary expansion was completed in the microwave oven. The type and content of press cake, as well as the type of product, significantly influenced total polyphenol content and antioxidant activity. Press cakes increased the contents of both soluble and insoluble fibre (from 1.94% d. m. and 1.28% d. m. for extrudates without press cakes up to 3.17% d. m. and 6.94% d. m. for SCFX extrudates with press cakes, respectively), and resistant starch was not markedly influenced by their addition. The influence of the content of press cake on HMF was not significant, whereas the type of cake and the type of extrusion influenced HMF significantly. In a raw mixture of corn grits with 3% of pumpkin press cake, HMF was below the limit of detection, and the highest content was found in the classically extruded sample with the addition of 9% of camelina press cake (580 ppb). In all samples, the acrylamide content was below the limit of detection, indicating that safe products were obtained. This research shows potential for the implementation of supercritical CO2 extrusion in the production of safe, nutritionally improved snack products. Future research might bring about the design of cost-effective processes applicable in the industry.

Carotenoid Content and Profiles of Pumpkin Products and By-Products

The goal of this review is to provide an overview of the current findings on the major carotenoids and their content in pumpkin products and by-products. The content of total carotenoids and the composition of carotenoids in pumpkins depend mainly on the species and cultivar, pedoclimatic conditions, the part of the plant (pulp, peel or seed), extraction procedures and the type of solvent used for extraction. The major carotenoids identified in pumpkins were β-carotene, α-carotene, lutein and zeaxanthin. β-Carotene is the major carotenoid in most pumpkin species. The number and content of total carotenoids are higher when minor carotenoids and ester forms are considered. The use of carotenoids in the development of functional foods has been the topic of many versatile studies in recent years, as they add significant value to foods associated with numerous health benefits. In view of this, pumpkin and pumpkin by-products can serve as a valuable source of carotenoids.

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.

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.

The Effect of Selected Fruit Juice Concentrates Used as Osmotic Agents on the Drying Kinetics and Chemical Properties of Vacuum-Microwave Drying of Pumpkin

The study examined the osmotic dehydration of pumpkin slices in chokeberry, flowering quince, and raspberry concentrated juices. Products obtained were subjected to vacuum-microwave finish drying (VMD). The objective of the study was to evaluate the drying kinetics and the chemical properties, that is, total polyphenolics content and antioxidant capacity of the vacuum-microwave-dried pumpkin products. The concentration and temperature of the juices were 40°Brix and 45°C, respectively. The pumpkin slices were pretreated in concentrated juices for 0.5, 1, 2, 3, and 6 hours. Vacuum-microwave finish drying was carried out at the power of magnetrons that ensured the maintenance of the safe temperature (below 90°C) of the slices measured with the use of infrared camera. The results of the study showed that the moisture content of samples during the pretreatment in concentrated juices was decreasing until the equilibrium stage. The logarithmic model was used to describe the drying kinetics of pumpkin during VMD. Osmotic pretreatment resulted in a decrease in colour coordinates, improved the antioxidant activity of dried product, and prolonged the duration of VMD.

Corn Crisps Enriched in Omega-3 Fatty Acids Sensory Characteristic and its Changes During Storage

Extruded cereal snacks are usually deficient in protein, mineral ingredients, valuable fatty acids. With the rise of health awareness among consumers, food manufacturers and scientists are pressed to take measures in order to develop new functional/health-beneficial foods. The aim of this work was to manufacture extruded crisps enriched with α-linolenic acid (obtained from linseed oil) and to observe whether storage of the product for the period of 6 months would cause its disqualification, primarily due to its sensory properties and secondarily due to its chemical properties. The research demonstrated that the addition of linseed oil to corn crisps at the amount of 5 % enables to obtain functional corn crisps containing over 2 g of ALA in a portion of 100 g even after 6 months of storage at room temperature. ALA-enriched crisps maintain the original sensory profile after 6 months of storage and their sensory profile is similar to the profile of crisps without the addition of linseed oil if they are packed in barrier packaging filled 100 % with argon. Therefore, they may be a healthier alternative to typical corn crisps.

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.