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- Liquefaction optimization of Crataegus monogyna JacqPublication . Dulyanska, Y; Cruz-Lopes, Luísa; Esteves, Bruno; Domingos, Idalina; Ferreira, José; Guiné, Raquel; Gonçalves, Fernando Jorge; Carvalho, L B; Barroca, M JThe objective of this work was to evaluate the potentiality of Crataegus monogyna Jacq. residues to be liquefied by polyhydric alcohols and the chemical transformations observed in this process with subsequent use to produce polyurethane foams. The variations on liquefaction yield were determined at different temperature, time, material/solvent ratio and granulometry. Results show that liquefaction performed at 180 °C with a 1:10 material/solvent ratio increases along time, reaching a maximum at 60 min. Similarly, liquefactions made during 60 min with a 1:10 material/solvent ratio show that there is an increase in liquefaction yield with the increase in temperature until 180 °C. A higher temperature could increase the liquefaction yield but would lead to a higher energy consumption in the process. There seems to be no significative advantage in increasing material/solvent ratio above 1:7, although the liquefaction yield increases for higher ratios. Granulometry testing shows that the smaller the particle the best is the liquefaction percentage. It was concluded that the best liquefaction yield, of approximately 81%, was obtained with a temperature of 180 °C, for 60 min and particle size <80 mesh for Crataegus monogyna Jacq. This material has good properties to be converted in a liquid mixture that can be used later, on the production of polyurethane foams.
- Production and characterization of powder from drone brood of honeybees (Apis mellifera)Publication . Goncalves, J. C.; Vouga, Beatriz; Costa, Cristina Amaro Da; Gonçalves, Fernando Jorge; Coelho, Catarina; Guiné, Raquel; Correia, PaulaDrone bee brood are a natural source of food with potential for human nutrition. This work aims to investigate the production and extraction of the drone bee brood (larvae and pupae), as well as the production of powder from this insect for food applications. To produce the drone brood (DB), in some hives of the colony appropriate empty frames were placed. Some measurements were done in the hive to monitor the global wellbeing of the colony, namely, temperature, relative humidity, and weight. After approximately one month, the frames were removed from the hives and frozen. The yield of DB by frame was 38%. For the extraction of the drone brood, different methods were tested, being the best ones the cold room extraction (∼ 6.5 °C), on a cold surface extraction (∼ 11 °C), and in boiling water extraction (100 °C). The results show that the extraction efficiencies were 74.3% (336.3 s), 62.5% (246.8 s) and 84.9% (332.0 s), for extraction in a cold room, on a cold surface, and in boiling water, respectively. After extraction, two drying processes were tested: evaporation and freeze-drying, being the last one the recommended, preserving in a better way the appearance and composition of the DB. DB powders presented different colour characteristics according to the extraction method used. The powder obtained by boiling extraction was darker than the one produced with cold extraction. Powders are rich in protein, fat and carbohydrates, being the fat content quite high for DB powders produced by boiling extraction method.
- Evaluation of phenolic compounds and antioxidant activity in some edible flowersPublication . Gonçalves, Fernando Jorge; C. Goncalves, J.; Ferrão, Ana Cristina; Correia, Paula; Guiné, RaquelRecently, edible fl owers ( EF ) have aroused increased interest because of their aesthetic properties as well as potential health bene fi ts related to the occurrence of some bioactive compounds. Therefore, the aim of this work was to evaluate the total phenolics, anthocyanins, fl avonoids, and antioxidant activity ( AOA ) ( following DPPH and ABTS methods ) in eleven EF. The samples were subjected to three successive extraction steps using methanol, and these extracts were then analysed for the aforementioned properties using spectrophotometric methods. The obtained extracts were used for the quantification of phenolic composition and AOA. The results indicated that, among the fl owers analysed in this study, red rose, pink rose, and red carnation possessed the highest total phenolic contents ( 27.53, 23.30, and 18.17 mg g − 1 gallic acid equivalents, respectively ) , total anthocyanins ( 3.07, 1.97, and 4.47 mg g − 1 catechin equivalents [ CE ] , respectively ) , and AOA ( 12.07, 15.77, and 12.93 mg g − 1 TE, respectively, as given by the DPPH method or 8.23, 9.27 and 8.00 mg g − 1 TE, respectively, as given by the ABTS method ) . The flowers with highest fl avonoids contents were red carnation, Mexican marigold, and pink rose ( 17.50, 16.90, and 16.57 mg g − 1 CE, respectively ) . Cluster analysis grouped the analysed flowers into two groups, those richest in phenolics with AOA and those not so rich. Finally, some important correlations were observed between the total phenolics and the AOA. In conclusion, these fl owers could represent a potential source of natural compounds with antioxidant capacity.
- The Motivations for Consumption of Edible Insects: A Systematic ReviewPublication . Florença, Sofia G.; Guiné, Raquel; Gonçalves, Fernando Jorge; Barroca, Maria João; Ferreira, Manuela; Costa, Cristina Amaro Da; Correia, Paula; Cardoso, Ana Paula; Campos, Sofia; Anjos, Ofélia; Cunha, Luís MiguelThe consumption of edible insects (EI) is traditional in many parts of the world, but not in others. In fact, despite globalization and the multiple advantages pointed out about the consumption of EI, there are still many countries where entomophagy is seen with disgust and aversion. This systematic review aimed to examine the motivations that influence the consumption of EI in diverse cultures and understand if there are differences between Western countries (WC) and insect-eating countries (IEC). It further evaluated whether the degree of acceptability was influenced by the form of consumption of the insects (eating whole insects or foods containing insects). This literature review was conducted in November 2021 within three databases, Web of Science, PubMed and Scopus, according to the Preferred Reporting of Items for Systematic Reviews and Meta-analysis and using PRISMA directives. From a total of 245 studies, 31 were selected to be included in this review, based on the inclusion criteria defined: only original research articles, from 2010 or beyond, and written in English. The results indicated that the main motivations that determine the consumption of EI are related to gender, age, sustainability, nutritional value, sensory attributes, tradition/culture, food neophobia, disgust and familiarity/past experiences. Moreover, whereas in IEC, there is a greater focus on factors related to sensory attributes, availability, affordability and preferences, in WC, there is a bigger emphasis on determinants such as nutritional value, sustainability, benefits, familiarity/past experience, tradition/culture, food neophobia and disgust. Finally, it was observed that people in WC are more willing to accept food products containing insects rather than the whole insect, which is one of the most promising points to be addressed in the future. Overall, this review highlights that there are numerous factors influencing the consumption of edible insects, and differences between WC and IEC are clear in what concerns the motivations of consumers. Hence, targeting market segments and consumers’ characteristics has to be present when designing strategies to incentivize the consumption of EI in WC as a part of a global strategy for sustainability of food systems.