Study of physiological and textural properties of roasted peanuts defatted by an innovative oil extraction process. Correlation with consumer evaluation

The growing demands for novel low-fat products and health conscious awareness posed a strong incentive to develop a new efficient defatting process of high quality. In this study, mechanical oil extraction, reconstitution by soaking and roasting were conducted on peanuts followed by quantitative and qualitative studies on the morphological and textural properties of the defatted grains to investigate the best extraction parameters (water content, pressure, processing duration). The novelty of this defatting process lies in the use of a specific separation material to avoid irreversible deformation and damage. Instrumental results and consumer evaluation were extremely correlated and findings showed that defatting promotes better grain appearance and increase in expansion ratio, hardness, friability and work required to crush the roasted peanuts that become less crunchy. A multiple optimization, using Response Surface Methodology, resulted in the following optimal conditions: 13.2% d.b. water content, 12 MPa pressure and 19.2 min processing duration.Industrial relevance

• •This study was performed within the Lebanese food project and low-fat peanuts were produced in an industrial environment.
• •The work described is innovative in the process implementation and design, thus, results were recently patented under the following publication numbers LB-10,492 and LB-10,493.
• •This article reveals a novel process of defatting called MEPPI “Mechanical Extraction Preserving Product Integrity”, applied on hydrated peanuts (7 to 13% d.b.) using mechanical expression method at pressures varying between 4 and 10 MPa for different processing durations (10 to 30 min). The additional advantage of this process is that high oil extraction yields (attaining 70 to 80%) have been obtained without any recourse to conventional polluting agents such as chemicals (hexane, petroleum ether,...etc.). Only mechanical pressing and hydration by soaking have been used during this healthy, eco-friendly and cost effective defatting process.
• •By applying this new process, higher oil yields have been achieved with lower processing times (3–4 min) and lower pressures (< 10 MPa), lower irreversible deformation ratios (< 1%) and higher consumer acceptability (by preserving the sensory, textural, physiological and organoleptic qualities of the finished product etc.) than what was previously obtained.
• •Previous defatting processes were abandoned by the industries as they yielded high percentages of broken and cracked nuts with a harsh texture. Contrariwise, the novelty of this study lies in the use of a specific separation material to avoid irreversible deformation and damage during defatting and to preserve by that the appearance and texture of the finished product.
• •The results of the present study were significant and would be helpful for the food industries as the textural and morphological quality of the new product was studied and the process parameters were optimized for a better acceptance by the consumers.
• •These results demonstrated that this novel process has successfully found solutions to health conscious consumers who are in need of high protein crunchy snacks but of reduced fat, and to food industry by having developed a cost-effective method in comparison to current applications.
• •This innovative process can have a broader perspective by applying it to other snack products in order to reduce their fat content while preserving shape integrity, without using any chemical agent.

     

Textural Measurements and Product Quality of Restructured Sweetpotato French Fries

The objectives of this research were to investigate the applicability of using an alginate-calcium gelling system to produce a French fry-type product using high beta-carotene sweetpotato puree as the main ingredient and to compare four instrumental methods of texture measurement for this product type in relation to sensory textural properties. Sweetpotato puree made with Jewel cultivar sweetpotatoes was restructured using optimized alginate-calcium concentrations. A consumer panel scored sweetpotato fries containing 0.35 g alginate/100 g and 0.5 g CaSO₄/100 g highest for appearance, texture, flavor, and overall acceptability. A trained texture profile panel described the product with 15 texture notes. Of these attributes, nine sensory notes describing hardness, mastication shear, cohesiveness, springiness, moistness, and oiliness were highly correlated with some instrumental parameters (r=0.79-0.92) for measuring textural properties. The instrumental methods evaluated were instrumental texture profile analysis, three-point bending force, Kramer shear force, and puncture force. Among these instrumental methods, Kramer shear appeared to be the method of choice because of method's simplicity and high precision (coefficient of variation ≤10%).     

Alternative protein sources in Western diets: Food product development and consumer acceptance of spirulina-filled pasta

Spirulina (Arthrospira platensis) is currently being increasingly researched for its usability and suitability in human nutrition. The inclusion of alternative protein sources, such as spirulina, in familiar products is a possible strategy to nudge consumers towards dietary change in Western societies. Filled pasta variants with three levels of spirulina-soy-extrudate in the filling (10%, 30% or 50%) were developed and investigated for their sensory characteristics and consumer liking. Recipe development was based on the concepts of flavor-flavor learning (beet-ginger or tomato) and masking (lemon-basil) to account for the musty and earthy notes of the alga. Consumer tests were conducted in Germany (n = 139), the Netherlands (n = 137) and France (n = 144), and conventional sensory profiling was accomplished with trained panelists (n = 12). Consumers preferred the lemon-basil flavor over tomato and beet-ginger flavored fillings. As expected, liking decreased with increased extrudate content, regardless of the flavor. For all flavors expected liking was higher than liking after product exposure; for the lemon-basil flavor the gap was the smallest. It was shown that low general food neophobia and familiarity with spirulina promoted consumer liking. The sensory profiling revealed that the spirulina-soy-extrudate content affected all sensory attributes identified across all flavors, but for the tomato flavor the most. Overall, this study confirms that it is important to consider differences in consumer motivation as well as the product’s conceptual and intrinsic sensory characteristics in new product development.