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- Shelf‐life study of a Salicornia ramosissima vegetable salt: an alternative to kitchen saltPublication . Lima, Alexandre R.; Cristofoli, Nathana L.; Filippidis, Kyriakos; Barreira, Luísa; Vieira, MargaridaWaste of Salicornia ramosissima a halophyte plant used in gourmet cuisine, can be valorized after being dried and milled, becoming a vegetable salt, a healthier replacer of kitchen salt due to its lower sodium content (around 10-fold less) but still maintaining an intense salty taste. To study the shelf life of this vegetable salt from S. ramosissima, packed in a cylindrical aluminum box, an accelerated shelf-life testing (ASLT) was first carried out at 35, 40, 45, and 50 degrees C by monitoring color, moisture, and water activity (a(w)) throughout the storage period. Moisture and a(w) decreased at increasing temperature, but the color was not affected. The moisture sorption isotherms (MSIs) were next produced at 15, 25, 35, and 45 degrees C and relative humidity (RH: 6.5%-80%) using the static gravimetric method. Several mathematical models were tested to fit the MSI experimental data and finally the Oswin model was used to predict the moisture content. With this model, the isosteric heat was determined. A mass-balance model was used to predict shelf life and the equilibrium moisture content (M-e) during storage based on predetermined MSI and water vapor rate transmission (WVTR) data. The predicted shelf life of the package with and without adhesive tape around the lid was 35 and 80 days (25 degrees C, 75% RH) and 19 and 63 days (35 degrees C, 90% RH), respectively. Practical Applications By understanding the moisture sorption phenomenon in hygroscopic powders, this study can provide valuable data to the food industry dealing with such products. Being a microbiologically safe product due to its low a(w) and having color stabilized through previous drying, its mode of failure during storage proved to be the loss of its free-flowing capacity. A methodology to evaluate the shelf life of this hygroscopic product packed in a cylindrical aluminum box is described. There is a need to draw attention to the fact that, despite aluminum with a thickness of .23 mm is a very effective barrier to water vapor penetration, such package has an extremely small gap between the lid and body, which is hard to measure, yet allows water vapor to flow through the package at a rate that results in its shelf life being less than 3 months. Ways to overcome this issue are suggested.
- Role of food engineering in sustainabilityPublication . Vieira, Margarida; Silva, Cristina L.M.; Lopez-Gutierrez, Gustavo; Erdogdu, FerruhThe XII edition of the Iberoamerican Congress of Food Engineering (CIBIA), the biannual conference with large impact at the Ibero-American level, took place in Faro, Portugal in July 2019, at the University of Algarve, addressing the issue “Challenging Food Engineering as a Driver Towards Sustainable Food Processing“. This theme was chosen based on the fact that sustainability became the key concern of the 21st century considering the comfort of the future generations.
- CIBIA XII - Iberoamerican Congress of Food Engineering, 2019Publication . Cruz, Rui; SILVA, L. M.; Vieira, MargaridaClimate change enhanced the need to decarbonize the food production and supply chain covering food processing, packaging, transport, retailing, and end-of-life disposal. Today's way food products are offered to consumers contributes to 30% of the greenhouse emissions (GHE), which is more than 2 tons of CO₂ per person per year in the United States and Europe. Alternatives to decrease this number include lowering meat intake and replacing it with plant-based protein, as the highest greenhouse gas emissions are released during meat production. Another solution is using raw materials produced locally or in the surroundings to produce food products, avoiding food transportation in ships, airplanes, or trains from long distances or overseas. Replacing non-biodegradable materials in food products packaging with new, bio-based, and biodegradable ones is another suitable alternative. Also, reducing food waste is of crucial importance as its carbon emissions account for approximately 6% of GHE, mainly due to decomposing process of the organic matter in landfills.
- Advances in the food packaging production from Agri-Food waste and by-products: Market trends for a sustainable developmentPublication . Cristofoli, Nathana L.; Ribeiro Lima, Alexandre; Tchonkouang, Rose Daphnee; Quintino, Andreia; Vieira, MargaridaAgricultural waste has been a prominent environmental concern due to its significant negative impact on the environment when it is incinerated, disposed of in landfills, or burned. These scenarios promoted innovations in the food packaging sector using renewable resources, namely agri-food waste and by-products such as bagasse, pulps, roots, shells, straws, and wastewater for the extraction and isolation of biopolymers that are later transformed into packaging materials such as bioplastics, biofilms, paper, and cardboards, among others. In this context, the circular bioeconomy (CBE) model is shown in the literature as a viable alternative for designing more sustainable production chains. Moreover, the biorefinery concept has been one of the main links between the agri-food chain and the food packaging industry. This review article aimed to compile recent advances in the food packaging field, presenting main industrial and scientific innovations, economic data, and the challenges the food packaging sector has faced in favor of sustainable development.
- Valorisation of wasted immature tomato to innovative fermented functional foodsPublication . Pereira, Nelson; Farrokhi, Mahsa; Vida, Manuela; Lageiro, Manuela; Ramos, Ana Cristina; Vieira, Margarida; Alegria, Carla; Gonçalves, Elsa M.; Abreu, MartaIn this study, the lactic fermentation of immature tomatoes as a tool for food ingredient production was evaluated as a circular economy-oriented alternative for valorising industrial tomatoes that are unsuitable for processing and which have wasted away in large quantities in the field. Two lactic acid bacteria (LAB) were assessed as starter cultures in an immature tomato pulp fermentation to produce functional food ingredients with probiotic potential. The first trial evaluated the probiotic character of Lactiplantibacillus plantarum (LAB97, isolated from immature tomato microbiota) and Weissella paramesenteroides (C1090, from the INIAV collection) through in vitro gastrointestinal digestion simulation. The results showed that LAB97 and C1090 met the probiotic potential viability criterion by maintaining 6 log10 CFU/mL counts after in vitro simulation. The second trial assessed the LAB starters’ fermentative ability. Partially decontaminated (110 ◦C/2 min) immature tomato pulp was used to prepare the individually inoculated samples (Id: LAB97 and C1090). Non-inoculated samples, both with and without thermal treatment (Id: CTR-TT and CTR-NTT, respectively), were prepared as the controls. Fermentation was undertaken (25 ◦C, 100 rpm) for 14 days. Throughout storage (0, 24, 48, 72 h, 7, and 14 days), all the samples were tested for LAB and Y&M counts, titratable acidity (TA), solid soluble content (SSC), total phenolic content (TPC), antioxidant capacity (AOx), as well as for organic acids and phenolic profiles, and CIELab colour and sensory evaluation (14th day). The LAB growth reached ca. 9 log10 CFU/mL for all samples after 72 h. The LAB97 samples had an earlier and higher acidification rate than the remaining ones, and they were highly correlated to lactic acid increments. The inoculated samples showed a faster and higher decrease rate in their SSC levels when compared to the controls. A nearly two-fold increase (p < 0.05) during the fermentation, over time, was observed in all samples’ AOx and TPC (p < 0.05, r = 0.93; similar pattern). The LAB97 samples obtained the best sensory acceptance for flavour and overall appreciation scores when compared to the others. In conclusion, the L. plantarum LAB97 starter culture was selected as a novel probiotic candidate to obtain a potential probiotic ingredient from immature tomato fruits.
- Structural characterization of exopolysaccharides obtained from Porphyridium cruentum exhausted culture mediumPublication . Cristofoli, Nathana L.; Ribeiro Lima, Alexandre; Rosa Da Costa, Ana; Evtyugin, Dmitry; Silva, Carlos; Varela, João; Vieira, MargaridaMicroalgae produce and secrete large quantities of polysaccharides into the culture medium that is discarded when biomass is separated. The main objective of this study was to add value to the exhausted culture medium (ECM) of Porphyridium cruentum through the recovery of extracellular polysaccharides (EPS) by different extracting and purifying methods for the future biotechnological applications. The ECM was submitted to pre-cipitation with cold absolute ethanol, using ultrasound, dialysis, and trichloroacetic acid (TCA) as purification methods. The purification provided a lower yield, with higher car-bohydrate content. The TCA purified sample presented up to twice as much total carbo-hydrates as the non-purified samples, mainly composed of xylose, galactose, and glucose. Scanning Electron Microscopy (SEM) images showed the smooth structure of P. cruentum EPS, in which TCA post-treatment and dialysis allowed obtaining larger and purest par-ticles, being a good candidate for film making. Microalgal polymeric by-products are a sustainable source to recover valuable compounds, and the purification treatment proved to be an important step to valorize this material.(c) 2023 The Authors. Published by Elsevier Ltd on behalf of Institution of Chemical Engineers. This is an open access article under the CC BY-NC-ND license (http://creati-vecommons.org/licenses/by-nc-nd/4.0/).
- UV-C light: a promising preservation technology for vegetable-based nonsolid food productsPublication . Tchonkouang, Rose Daphnee; Ribeiro Lima, Alexandre; Quintino, Andreia; Cristofoli, Nathana L.; Vieira, MargaridaA variety of bioactive substances present in fruit- and vegetable-processed products have health-promoting properties. The consumption of nutrient-rich plant-based products is essential to address undernutrition and micronutrient deficiencies. Preservation is paramount in manufacturing plant-based nonsolid foods such as juices, purees, and sauces. Thermal processing has been widely used to preserve fruit- and vegetable-based products by reducing enzymatic and microbial activities, thereby ensuring safety and prolonged shelf life. However, the nutritional value of products is compromised due to the deleterious effects of thermal treatments on essential nutrients and bioactive compounds. To prevent the loss of nutrients associated with thermal treatment, alternative technologies are being researched extensively. In studies conducted on nonsolid food, UV-C treatment has been proven to preserve quality and minimize nutrient degradation. This review compiles information on the use of UV-C technology in preserving the nutritional attributes of nonsolid foods derived from fruit and vegetables. The legislation, market potential, consumer acceptance, and limitations of UV-C are reviewed.
- Food composition databases: does it matter to human health?Publication . Delgado, Amélia; Issaoui, Manel; Vieira, Margarida; Saraiva De Carvalho, Isabel; Fardet, AnthonyFood provides humans with more than just energy and nutrients, addressing both vital needs and pleasure. Food habits are determined by a wide range of factors, from sensorial stimuli to beliefs and, once commanded by local and seasonal availability, are nowadays driven by marketing campaigns promoting unhealthy and non-sustainable foodstuffs. Top-down and bottom-up changes are transforming food systems, driven by policies on SDGs and by consumer’s concerns about environmental and health impacts. Food quality, in terms of taste, safety, and nutritional value, is determined by its composition, described in food composition databases (FDBs). FDBs are then useful resources to agronomists, food and mechanical engineers, nutritionists, marketers, and others in their efforts to address at maximum human nutrient needs. In this work, we analyse some relevant food composition databases (viz., purpose, type of data, ease of access, regularity of updates), inspecting information on the health and environmental nexus, such as food origin, production mode as well as nutritional quality. The usefulness and limitations of food databases are discussed regarding what concerns sustainable diets, the food ‘matrix effect’, missing compounds, safe processing, and in guiding innovation in foods, as well as in shaping consumers’ perceptions and food choices.
- Comparative study of the production of cellulose nanofibers from agro-industrial waste streams of Salicornia ramosissima by acid and enzymatic treatmentPublication . Ribeiro Lima, Alexandre; Cristofoli, Nathana L.; Rosa Da Costa, Ana; Saraiva, Jorge A.; Vieira, MargaridaThe study of the suitability of two isolation processes to produce cellulose nanofibers (CNFs) from Salicornia ramosissima waste, with potential applicability as a reinforcing agent of polymeric composites was carried out. To separate the cellulose fibrils from the cell wall and obtain CNFs an alkaline treatment was applied followed by a bleaching treat-ment and, the insoluble residue was next hydrolyzed by either an acid treatment (AT) or an enzyme treatment (ET). SEM and TEM images indicated fiber exposure caused by both treatments. The diameter, length, aspect ratio, and polydispersity index, were measured for both CNFs. CNF (ET) showed high zeta potential values suggesting that ET produces more electrically stable and thinner nanofibers. The FTIR spectra revealed that both treatments effectively removed the amorphous components allowing the CNFs isolation, and XRD patterns evidenced the increase in the degree of crystallinity of both CNFs. Nonetheless, CNF(AT) presented a lower mechanical resistance due to its smaller particle size, compared to the CNF(ET). In summary, the (ET) could successfully isolate CNFs from the Salicornia waste, encouraging the use of this treatment, once when compared to (AT), it does not generate toxic residues, presents mild thermal conditions, and produces CNFs with higher-value applications.
- Particle size effect of integral carob flour on bioaccessibility of bioactive compounds during simulated gastrointestinal digestionPublication . Vilas-Boas, Ana M.; Brassesco, María E.; Quintino, Andreia; Vieira, Margarida; Brandão, Teresa R. S.; Silva, Cristina L. M.; Azevedo, Miguel; Pintado, ManuelaCarob fruit is native to the Mediterranean region and produced mainly in Portugal, Italy, Morocco and Turkey. The production of the carob fruit in Portugal is highly extensive and sustainable. Currently, carob flour (CF) production is mainly achieved after pulp separation, despite it having been demonstrated that the seeds improve the extraction efficiency of bioactive compounds such as polyphenols, promoting human health. This study aimed to produce an integral CF through an innovative process and assess its physicochemical and bioactive properties at different particle sizes throughout simulated gastrointestinal tract (GIT) digestion. The sugar content profile obtained throughout GIT digestion indicated that sucrose, the sugar present at the highest concentration in undigested CF, was digested and broken down into simple sugars, namely glucose and fructose. The total phenolic content (TPC) and antioxidant activity obtained for the ≤100 µm fraction were in accordance and gastric digestion promoted an increase in the TPC value compared to the undigested sample. The >100 µm fractions displayed a distinct profile from the ≤100 µm fraction. This study showed that the particle size affects the sugar, antioxidant and total phenolic content of CFs and also their gastrointestinal tract digestion. The ≤100 µm fraction demonstrated the most suitable profile as a functional food ingredient.