PulpIng - Development of a Pumpkin Pulp Formulation using a Sustainable Integrated Strategy

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Recuperação de subprodutos da indústria alimentar para extração otimizada de compostos fenólicos

Publication . Leichtweis, Maria Gabriela; Molina, Adriana K.; Pereira, Carla; Carocho, Márcio; Vassilou, Charikleia; Petropoulos, Spyridon Α.; Oliveira, Beatriz; Ferreira, Isabel C.F.R.; Barros, Lillian

Uma vertente muito importante da economia circular é a sustentabilidade. Alcançar metas como a redução do desperdício de alimentos e a minimização do consumo de energia e de produtos poluentes tem sido o foco de vários estudos recentes que visam a identificação da dinâmica de produção de bio-resíduos e subprodutos da indústria alimentar e a possibilidade de reaproveitamento dos mesmos [1]. Assim, o presente estudo visa a recuperação sustentável de subprodutos da indústria alimentar, nomeadamente de cascas de abóbora descartadas ao longo do processo de produção de polpas. Nesse sentido, as cascas de abóbora Grega ‘Leuka Melitis’ foram utilizadas para a obtenção de extratos ricos em compostos fenólicos através de duas técnicas deextração: maceração (M) e ultrassons (U). A otimização destes processos foi realizada recorrendo à metodologia de superfície de resposta (RSM) baseada no desenho experimental Box-Behnken, considerando como variáveis independentes o tempo de extração, a temperatura (MAC) ou potência (EAU) e a concentração de etanol no solvente, e como variáreis dependentes o rendimento de extração (resíduo seco) e a concentração de fenóis totais (método de Fólin-Ciocalteu). Para ambas as respostas, o método alternativo de extração assistida por ultrassons demonstrou ser o mais vantajoso, especialmente no que respeita à concentração de compostos fenólicos totais, permitindo duplicar a concentração destes compostos, relativamente à maceração. Esta técnica permitiu ainda minimizar o tempo de extração, especialmente do que respeita ao rendimento, e diminuir a potência aplicada. De entre as três variáveis independentes analisadas, a concentração de etanol no solvente de extração foi a que apresentou maior influência em ambas as variáveis dependentes. No geral, concentrações mais elevadas de etanol levaram a rendimentos de extração inferiores, mas a teores mais elevados de compostos fenólicos nos extratos, revelando assim maior eficácia na recuperação de bioativos. Os resultados apresentados corroboram a importância da recuperação de subprodutos da indústria alimentar para o desenvolvimento de extratos ricos em compostos bioativos, bem como a eficácia de técnicas alternativas de extração, permitindo a diminuição do desperdício de subprodutos e de energia.

2022Conference object

Open access

Pumpkin bioresidues as sources of bioactive compounds for food application

Publication . Leichtweis, Maria Gabriela; Molina, Adriana K.; Pereira, Carla; Pires, Tânia C.S.P.; Ferreira, Isabel C.F.R.; Barros, Lillian

According to FAO data, in Europe, almost half of fruit and vegetable production is lost or wasted [1]. Part of this occurs in the industry during processing stages of these commodities, resulting in huge amounts of waste in the form of peels, seeds, liquid, and molasses [2]. Nevertheless, these residues are rich in organic matter, phytochemicals, and compounds with nutraceutical properties [3]. Focusing on the valorisation of these residues, which compounds have commercial potential and aiming at promoting a circular economy, the present work focused the evaluation of the bioactive properties of the bioresidues generated in pumpkin pulp production. For this purpose, the peel, seeds, and fibrous strands of three pumpkin varieties grown in Portugal (butternut squash, common pumpkin, and kabocha squash) were evaluated in terms of antioxidant capacity, through 3 chemical (DPPH scavenging activity, reducing power and β-carotene bleaching inhibition) and 2 biological (TBARS and OxHLIA) methods. Additionally, their cytotoxicity was assessed through the in vitro sulforodamine B (SRB) assay, tested in a primary culture of cells prepared from porcine liver. Regarding the antioxidant activity evaluation, all the samples presented great antioxidant capacity, showing IC50 values ranging from about 50 times higher than the positive control, Trolox, to about 14 times lower than Trolox. The fibrous strands and seeds showed better antioxidant capacity than the peels, with the fibrous strands revealing great antioxidant capacity in the employed chemical methods, and the seeds in the biological ones. In terms of pumpkin varieties, the kabocha squash presented the best result in 3 of the 5 assays (DPPH, β-carotene, and TBARS). Regarding cytotoxicity, the effect of inhibiting non-tumour cell growth was not observed for any of the samples, even at the highest concentration (400 μg/mL), which is of great importance for considering their inclusion into foodstuff. These preliminary results showed a great potential for the exploration of pumpkin bioresidues to develop natural additives with antioxidant properties to be included in food products, fostering the circular economy.

2021Conference object

Open access

Sustainable use of pumpkin: characterization of the pulp and valorization of by-products in obtaining preservative extracts

Publication . Leichtweis, Maria Gabriela; Molina, Adriana K.; Pereira, Carla; Pires, Tânia C.S.P.; Calhelha, Ricardo C.; Mohamed, Mustafa H.M.; Oliveira, Beatriz; Ferreira, Isabel C.F.R.; Barros, Lillian

In the search for more sustainable industrial processes, the use of by-products from food production is an important strand [1]. Currently, the food industry has increasingly developed practical, ready-to-eat, and long shelf-life food products. How ever, this demand involves the use of synthetic food additives, which are associated with harmful effects on consumers health. Aiming to promote sustainability allied to the replacement of synthetic additives by natural alternatives, this work proposed the use of by-products from pumpkin processing, as a matrix for obtaining preservative compounds with potential to be applied in a product of pumpkin pulp. For that purpose, five different pumpkins cultivated in Egypt, namely ‘Butternut Squash’, ‘Golden Cushaw’, ‘Dickinson’, ‘Halloween’, and ‘Honey Delite’ were assessed. The pulp was evaluated regarding its nutritional value and chemical composition, in terms of free sugars (HPLC-RI), fatty acids (GC-FID), tocopherols (HPLC-FLD) and organic acids (UFLC-PDA). The by-products, more specifically the seeds, fibers, and peel, were evaluated for their antioxidant and antimicrobial capacity, as well as their cytotoxicity. All the pulp samples presented carbohydrates as the major compounds, followed by protein and fibers, with low content of fat. Regarding free sugars, fructose was predominant in all samples, except for the ‘Golden Cushaw’, which presented high levels of sucrose. Glucose was also present in high levels in most of the samples, and considerable contents of trehalose and raffinose were also found. Regarding fatty acids profile, the pulp revealed to be rich in saturated and polyunsaturated fatty acids, representing, respectively, about 40-50% of the total fatty acids, composed mainly by palmitic (C16:0), linoleic (C18:2n6c), α-linolenic (C18:3n3), and stearic (C18:0) acids. Regarding organic acids, all pulp samples presented malic and fumaric acids. In the samples that presented quinic acid, this was present in major quantity. Oxalic acid and traces of shikimic and citric acids were also detected. Also, the samples showed αand γisoforms of tocopherol, being the last one the most abundant. In addition to the rich nutritional composition of the pulps, as expected, the by-product extracts showed excellent preservative capacity. In the TBARS assay, the samples showed great capacity to inhibit lipid peroxidation, mainly the seeds and two of the five fibers. Moreover, all samples presented antibacterial capacity, inhibiting the growth of one to six of the eight tested bacteria. Also, some samples were capable of inhibiting the growth of the two fungal strains tested, with the peels standing out, protecting against at least three bacteria and one fungus. Additionally, none of the samples presented cytotoxic activity against the non-tumor porcine liver cells (up to 400 μg/mL), thus expressing its safety for food application. With this, it is possible to verify the potential use of pumpkin by-products as a source of natural preservatives, as well as the great nutritional value of the pulp, which can be further explored in the development of new pulp products preserved with their processing by-products. This favours a circular economy through sustainability.

2023Conference object

Open access

Integrative and sustainable strategy for the valorization of pumpkin by-products

Publication . Leichtweis, Maria Gabriela; Molina, Adriana K.; Pires, Tânia C.S.P.; Pereira, Carla; Oliveira, Beatriz; Ferreira, Isabel C.F.R.; Barros, Lillian

The food industry has sought to meet consumers’ demand for practical, ready-to-eatfoods capable of meeting daily nutritional needs and providing pleasure and satiety. However, the industry still relies on artificial additives to preserve and improve food properties, due to the lack of effective natural analogues, which face stability and availability limitations [1]. Aiming at the objectives of the circular economy and the promotion of more sustainable agro-industrial processes, the ambition of this project is to develop a new pumpkin fruit pulp formulation functionalised with a biobased preservative extracted from pumpkin by-products. For that purpose, production protocols will be established to ensure high agronomic performance and high-quality pumpkins. Meanwhile, pumpkin pulps will be evaluated in terms of nutritional value and the by-products, as seeds, peels, and fibers, will be assessed for their content in preservative compounds. The recovered, refined, and stabilized preservative compounds will further be incorporated in the pumpkin product formulated with the pumpkin elite cultivars. In addition, the quality assessment of pumpkin fruit pulp during shelf-life and the waste and wastewater management are targeted. The proposed project involves multidisciplinary research groups (IPB/PT, MORE/PT, UTH/GR, GFV/GR, CBBC/TN, ATB/DE, CRAPC/DZ, BU/EG) with various expertise in the food and farming sector, and the company DECORGEL/PT, which will further process the pumpkin pulp to be “market ready”, within the consortium PRIMA Section 2 - Multi-topic 2019: PulpIng (PRIMA/0007/2019). The described aims are in line with the EU Biodiversity Strategy of 2020 and 2030 Agenda for Sustainable Development, and intend to address food safety/security issues and promote circular food systems in Mediterranean regions.

2023Conference object

Open access

Food industry by-products applied as pumpkin-based foodstuff preservatives

Publication . Leichtweis, Maria Gabriela; Molina, Adriana K.; Pereira, Carla; Chaski, Christina; Polyzos, Nikolaos; Petropoulos, Spyridon Α.; Ferreira, Isabel C.F.R.; Barros, Lillian

Pumpkin is traditionally cultivated and consumed worldwide, being the fruit and its by-products recognized by their nutritional and health benefits. In the current pandemic scenario and towards a circular economy, the development of a healthy and green technological food product was proposed using pumpkin pulp enriched with bioactive compounds obtained from pumpkin by-products. The seeds, rinds, and fibrous placenta of seventeen different pumpkin genotypes from Greece were assessed for their antioxidant properties (TBARS), while the pulp was evaluated in terms of ash, protein, fat, and carbohydrate contents by AOAC methods¹. The free sugars profiles were obtained by HPLC-RI. All pumpkin by-products revealed great antioxidant properties, demonstrating their ability to inhibit lipid peroxidation and suggesting their potential application as sources of preservative compounds. All pulp samples recorded carbohydrates as the major compounds, with contents of about 67-86%, followed by protein (about 8-21%) and fat (about 0,4-1,1%). The ash content ranged from about 3,5 to 11%. Regarding free sugars, two predominant profiles were traced: one rich in fructose and glucose and low in sucrose, and another one with opposite prevalence (Figure 1). These results corroborate the great nutritional value of pumpkin genotypes from Greece and reveal the potential use of pumpkin by-products in the development of preservative solutions to maintain the pulp quality and safety over storage time, through the development of pumpkin-based food products.

2021Conference object

Open access