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- Study of the proximate and mineral composition of different Nigerian yam chips, flakes and floursPublication . Omohimi, C. I.; Piccirillo, C.; Roriz, M.; Ferraro, V.; Vasconcelos, M. W.; Sanni, L. O.; Tomlins, K.; Pintado, M. M.; Abayomi, L. A.Yam (Dioscorea spp) is an essential tuber crop for hundreds of millions of people in many African, Asian and South American countries. Considering in particular Southwest Nigeria, chips, flakes and flours are amongst the most common shelf-stable traditionally-processed yam products. This paper reports a systematic study on the proximate (moisture, protein, carbohydrate, fibre, fat, ash and gross energy) and mineral composition of these three food commodities sold in Nigerian markets. Results showed no significant differences in the moisture, crude protein and fibre content of all samples (10.0–12.3, 2.7–4.3 and 1.3–2.0 wt%, respectively). Gross energy was also comparable for all yam derived food items (between 3300 and 3507 kcal/kg), contradicting the common belief that yam flakes have lower nutritional value than chips and flours. Considering the mineral composition, Ca, Mg, P and K were the predominant macronutrients. Micronutrients such as Zn, Co, Mn and Cu were also detected. Significant differences existed between products, and their various sources (markets). Principal component analysis showed a direct correlation between ash content of the samples and the assessed macronutrients, irrespective of the market, or the seller of the commodities. This study confirmed that yam derived food stuffs have an adequate nutritional composition, irrespective of their form and/or origin.
- Potential valorisation of vinification by-productsPublication . Santos, A. F.; Ferraro, V.; Cruz, I. B.; Ferreira Jorge, R.; Carvalho, A. P.; Castro, P. M. L.; Pintado, M. E.
- Cassava (manihot esculenta crantz) and yam (dioscorea spp.) crops and their derived foodstuffs: safety, security and nutritional valuePublication . Ferraro, Vincenza; Piccirillo, Clara; Tomlins, Keith; Pintado, M. E.Cassava (Manihot esculenta Crantz) and yam (Dioscorea spp.) are tropical crops consumed by ca. 2 billion people and represent the main source of carbohydrate and energy for the approximately 700million people living in the tropical and sub-tropical areas. They are a guarantee of food security for developing countries. The production of these crops and the transformation into food-derived commodities is increasing, it represents a profitable business and farmers generate substantial income from their market. However, there are some important concerns related to the food safety and food security. The high post-harvest losses, mainly for yam, the contamination by endogenous toxic compounds, mainly for cassava, and the contamination by external agents (such as micotoxins, pesticides, and heavy metal) represent a depletion of economic value and income. The loss in the raw crops or the impossibility to market the derived foodstuffs, due to incompliance with food regulations, can seriously limit all yam tubers and the cassava roots processors, from farmers to household, from small-medium to large enterprises. One of the greatest challenges to overcome those concerns is the transformation of traditional or indigenous processing methods into modern industrial operations, from the crop storage to the adequate package of each derived foodstuff.
- Characterization of high added values compounds in drained water during the codfish (Gadus morhua) salting processPublication . Ferraro, V.; Cruz, I. B; Ferreira, R. Jorge; Malcata, F. X.; Castro, Paula M. L.; Pintado, M. E.
- Study of the mineral composition of different Nigerian yam floursPublication . Piccirillo, Clara; Vincenza, Ferraro; Roriz, Mariana; Omohimi, Celstina; Abayomi, Louise A.; Vasconcelos, Marta W.; Sanni, Lateef; Pintado, ManuelaYam is a root crop essential for the lives of hundreds of millions of people in many African, Asian and South American countries. Yam roots are in fact used to produce a variety of food items, including yam flour. The flours are consumed mainly as a source of carbohydrate; however, they also supply several minerals which are essential for good state of health. In this study we report about a systematic investigation on the mineral composition of several Nigerian yam flours. More than 40 flours samples purchased from local market vendors and/or producers were analysed by ICP-OES spectrometry; the concentration of minerals (i.e. potassium, sodium, iron, etc.) was determined. Results showed variance in the mineral profile across different sources of the flour. This research also highlighted the nutritional potential of yam flours and allowed possible regional variations in the flour compositions to be monitored.
- Valorisation of natural extracts from marine source focused on marine by-products: A reviewPublication . Ferraro, Vincenza; Cruz, Isabel B.; Jorge, Ruben Ferreira; Malcata, F. Xavier; Pintado, Manuela E.; Castro, Paula M.L.The wide chemical and biological diversity observed in the marine environment makes the ocean an extraordinary source of high added value compounds (HAVC) which can be employed in many applications. Minerals, lipids, amino acids, polysaccharides and proteins from marine sources have unique features and, surprisingly, their highest concentration is often found in parts of marine organisms that are commonly discarded. Fish heads, viscera, skin, tails, offal and blood, as well as seafood shells possess several HAVC suitable for human health applications, yet most end up as residues throughout the raw material processing. This review updates information on this issue and conveys critical analysis of the chief methodologies to carry out extraction, purification and eventual transformation, with a focus on their actual and potential applications.
- Extraction of high added value biological compounds from sardine, sardine-type fish and mackerel canning residues - a reviewPublication . Ferraro, Vincenza; Carvalho, Ana P.; Piccirillo, Clara; Santos, Manuela M.; Castro, Paula M. L.; Pintado, Manuela E.Different valuable compounds, which can be employed in medicine or in other industries (i.e. food, agro-chemical, pharmaceutical) can be recovered from by-products and waste from the fish canning industries. They include lipids, proteins, bio-polymers, minerals, amino acids and enzymes; they can be extracted from wastewaters and/or from solid residues (head, viscera, skin, tails and flesh) generated along the canning process, through the filleting, cooking, salting or smoking stages. In this review, the opportunities for the extraction and the valorisation of bioactive compounds from sardine, sardine-type fish and mackerel canning residues are examined and discussed. These are amongst the most consumed fishes in the Mediterranean area; moreover, canning is one of the most important and common methods of preservation. The large quantities of by-products generated have great potentials for the extraction of biologically desirable high added value compounds.
- Potential valorisation of vinification by-productsPublication . Santos, A. F.; Ferraro, V.; Cruz, I. B.; Jorge, R. F.; Carvalho, A. P.; Castro, P. M. L.; Pintado, M. E.
- Characterisation of soluble nitrogen and muscle proteins in wastewater throughout the salting process of Codfish (Gadus morhua)Publication . Ferraro, Vincenza; Cruz, Isabel B.; Jorge, Ruben Ferreira; Malcata, F. Xavier; Castro, Paula M. L.; Pintado, Manuela E.In Portugal, Atlantic codfish (Gadus morhua) is usually consumed after dry salting; this process is carried out by mixing deboned codfish with food–grade marine salt followed by stacking in a tank for 6 days. Along the salting process, codfish incorporates salt as well as it is partially dried by the release of water - up to 22 % (w/w). Currently, this wastewater is treated as a residue not being further valorized. However, the presence of a significant amount of valuable compounds in this rest, such as amino acids and proteins, may allow for valorization opportunities not yet explored. The present work focuses on the identification of the nitrogen-containing compounds present in such wastewater. Total nitrogen (WSN), trichloroacetic acid-soluble nitrogen (TCASN) and phosphotungstic acid-soluble nitrogen (PTASN) were evaluated by the micro-Kjeldahl method; Biuret method was used for total protein determinations and SDS-Page was performed for protein molecular weight screening. The results revealed an increase of WSN, TCASN and PTASN with time, with corresponding values of 3.17 g/L (WSN), 1.62 g/L (TCASN) and 1.16 g/L (PTASN) by the end of the process; the evolution of WSN versus the released water was approximately constant during the salting process, as well as the ratios of TCASN/WSN and PTASN/WSN with values of 51.25 and 36.55 % (w/w) at equilibrium, respectively.
- Valorisation of codfish (Gadus morhua L.) salting processing wastewater through the extraction of high added value compoundsPublication . Ferraro, Vincenza; Castro, Paula Maria Lima; Pintado, Maria Manuela EstevezApesar do desenvolvimento de outros métodos de preservação, a salga do bacalhau (Gadus morhua L.) continua a ser uma realidade devido a um conjunto de factores, entre os quais a simplicidade e o baixo custo do processo bem como as características sensoriais do produto final, muito apreciadas pelos consumidores. Ao longo do processo de salga o bacalhau incorpora sal até 20% do seu peso e liberta concomitantemente cerca de 22% da sua água fisiológica; assim, aproximadamente 200 litros de água residual salgada são gerados para cada tonelada de bacalhau fresco. Esse efluente é actualmente tratado como resíduo tóxico devido ao alto teor de cloro, que pode atingir valores de concentração de cerca de 160 g/L. A libertação desta água trás como consequência alterações significativas na composição e na estrutura do tecido muscular do bacalhau, levando à perda de compostos bioativos importantes, entre os quais aminoácidos livres, peptídeos e proteínas, nutrientes que, embora não essenciais, podem ser benéficos em certas circunstâncias. Assim, a recuperação de compostos orgánicos e do sal marinho de grau alimentar utilizado no processo de salga pode contribuir para a gestão integrada da água residual em questão. Com este objetivo, o perfil químico da água libertada foi avaliado. No final do período de salga o conteúdo de matéria seca na água libertada atinge o valor de ca. 10 g/L. A concentração de aminoácidos livres aumentou de 3.5 g/L a 6.5 g/L em 6 dias, devido a fenómenos de proteólise. Creatina, ácidos aspártico e glutâmico, arginina, glicina, metionina, lisina, taurina e triptofano, foram os aminoácidos livres predominantes e cuja libertação demonstrou-se obedecer a uma cinética monomolecular ou de pseudo-segunda ordem, dependendo do aminoácido. Embora em menor escala, a concentração de proteínas miofibrilares também aumentou com o tempo – de 3 para 3.7 g/L – fenómeno este ainda atribuível à proteólise. A análise do azoto total e as suas fracções mostraram que, no final do processo de salga, 36.6% (w/w) de azoto total corresponde a peptídeos curtos com até 20 residuos e a aminoácidos livres, 14.7% (w/w) aos peptídeos com mais de 20 residuos e os restantes 48.7% (w/w) às proteínas. A concentração total de aminas biogénicas na água no final do processo de salga foi de ca. 100 mg/kg. Proteínas, peptídeos a aminoácidos foram recuperados com sucesso por meio de um processo de sorção em batch e após um pré-tratamento com etanol de grau alimentar de forma a reduzir a concentração de sal da água, cuja elevada concentração, ca. 4.3 M, demonstrou afectar negativamente o mecanismo de adsorção dos aminoácidos. A presença do sal em certas concentrações demonstrou-se no entanto ser positiva, devido ao efeito da força iónica sobre a adsorção de aminoácidos. A resina polimérica comercial Amberlite XAD16, uma resina neutra e não-polar, foi seleccionada para prosseguir com estudos de adsorção. Aminoácidos livres, proteínas e peptideos foram adsorvidos no mesmo estágio. O processo de recuperação foi efectuado recorrendo a solventes de grau alimentar. Foi efectuada uma análise paramétrica do processo de adsorção examinando o efeito de diferentes parâmetros, nomeadamente temperatura, pH, percentagem de etanol adicionado a água residual, agitação, força iónica da solução, quantidade de adsorvente. O volume de solvente eluente e a temperatura foram os parâmetros avaliados na etapa de desadsorção. Os resultados mostraram que o processo de adsorção é controlado pela temperatura e pela força iónica, a qual neutraliza os efeitos do pH, e que a desadsorção é controlada pela temperatura e pela natureza do solvente eluente. A acetona resultou como o melhor solvente para desadsorção de aminoácidos livres, com um rendimento de recuperação de aminoácidos hidrofobicos e neutros de 100 %. As proteínas foram desadsorvidas por uma solução básica de hidróxido de sódio em água ao 4% (w/v), com um rendimento de recuperação de 100 %. Os aminoácidos livres extraídos da água residual mostraram actividade antioxidante em geral e de proteção do DNA contra a oxidação em particular. Para os mesmos aminoácidos, a biodisponibilidade in-vitro foi estudada usando celulas Caco-2, medindo a taxa de transporte paracelular e a resistência elétrica transepitelial para verificar a integridade das células do epitelio intestinal. Os resultados mostraram que todos os aminoácidos livres extraídos permearam através da monocamada celular intestinal, embora em taxas diferentes e dependendo da sua concentração inicial; o transporte foi superior a 90 % para todos os aminoácidos livres, excepto a creatina, cujo transporte não passou de 6 %. A presença de sal na solução teve um papel positivo sendo o cloreto de sódio entre os mais importantes osmólitos de aminoácidos em seres humanos.
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