Possibility to Save Water and Energy by Application of Fresh Vegetables to Produce Supplemented Potato-Based Snack Pellets

Abstract

The aim of the study was to examine the effect of fresh vegetable addition on processing efficiency, and to ascertain the energy and water consumption during production of potato-based snack pellets. The extrusion-cooking process with a modified single screw extruder was applied at variable screw speeds and amounts of vegetable additives. A mixture of potato flakes, potato grits and starch was used as a basic recipe. The potato composition was supplemented with fresh pulp of onion, leek, kale and carrot in amounts of 2.5–30.0% as replacement of a related amount of potato starch. The water consumption, as well as processing indicators: the production efficiency, the specific mechanical energy (SME), and the total SME requirements during snack pellets processing at the laboratory scale were evaluated. As a result of this work, we found that the amount of applied vegetable additives had little impact on both processing efficiency and SME depending on the screw speeds applied. Moreover, we saw increased processing efficiency with increased screw speed during extrusion. Of particular note, maximum value of processing efficiency was observed if fresh onion was used as an additive at the highest speed screw. Furthermore, the lowest specific mechanical energy consumption was noted for extrudates supplemented with fresh onion addition processed at the lowest screw speed. The most important limiting of water consumption during processing without negative effects on processing efficiency and quality of the final snack pellets was observed if 20% to 30% of fresh vegetables were used in the recipe. We believe that application of fresh vegetable pulp limited the energy requirements by mitigating the drying process of additives.

Effect of Composition and Processing Conditions on Selected Properties of Potato-Based Pellets and Microwave-Expanded Snacks Supplemented with Fresh Beetroot Pulp

“…Moreover, because the extrusioncooking is a high-temperature process, the processing by its means can be used as a method of thermal sterilization. As previously presented [Lisiecka & Wójtowicz, 2020], the use of fresh vegetables can significantly reduce the water volume needed in the technological process and the energy needed for the drying process. Thus, the use of fresh vegetables as additives to this type of indirectly expanded snacks has many advantages.…”

“…The moisture content was assessed through employing a standard reference American Association of Cereal Chemists 44-15.02 air-oven method (130°C, 1 h) [AACC, 1995] both for dry components and for beetroot pulp after grinding. Calculation of water amount added was done in accordance to the previous paper [Lisiecka & Wójtowicz, 2020] to reach the moisture content of blends at 33 g/100 g (sum of water content in all components by weight). Firstly, dry components were mixed, then fresh pulp was added, mixed together, and the proper amount of water was added to each blend.…”

Characteristics of Newly Developed Extruded Products Supplemented with Plants in a Form of Microwave-Expanded Snacks

“…The carrots were carefully washed with tap water, dried using paper towels, and ground by employing an LMN-100 laboratory knife mill TestChem (Radlin, Poland) for granulation below 1 mm, to achieve fresh carrot pulp (FCP). The moisture content of all raw materials was checked according to Lisiecka and Wójtowicz [ 13 ].…”

“…The final moisture content of each blend (33%) was obtained by spraying the blended components with the appropriate amount of tap water and then mixing for 15 min. The amount of water was calculated based on the water content in all blend components, as described by Lisiecka and Wójtowicz [ 13 ], and thus, the application of fresh plant material significantly limited the water needed for processing.…”

“…Plant material such as fresh carrot pulp seems to be a valuable source of biologically active components, as well as a natural colorant. Moreover, as was assumed by Lisiecka and Wójtowicz [ 13 ], the application of fresh vegetable pulp is an efficient method to limit water and energy requirements during processing. Therefore, the present study is aimed at investigating the influence of the addition of varied fresh carrot content and variable screw speeds during processing on selected features of newly developed pellets and microwave-expanded snacks.…”