38 research outputs found
Determinaçao das características físicas de duas variedades de melâo (Cucumis melo L.).
O conhecimento preciso das características físicas dos frutos reveste-se do maior interesse pois permite minimizar as perdas por danos mecânicos, fornece dados para o desenho de novas maquinas e facilita a determinação das condições ideais de conservação. À determinação das características físicas de melão, a sua resistência aos danos físicos o seu comportamento quando sujeito a forças de deforma çao, sao estudadas mediante a utilização de diversos métodos. Foram seleccionadas duas variedades de melão ( Cucumis melo L.), as mais significativas em Espanha e Portugal respectivamente " Piei de Sapo " e " Melão Branco da Lezíria ". Ambos foram cultivados nas mesmas condições edafo-climáticas e sujeitos ã iguais práticas agronómicas, tendo sido os seus frutos sujeitos a diversos testes no " Laboratorio de Propiedades Físicas " da " Escola Técnica Superior de Ingenieros Agrónomos de Madrid ". Foram estudados diversos parâmetros como: " impact loading ", penetração, deformação e ruptura de frutos e ainda deformação e ruptura de amostras cilíndricas. O efeito do armazenamento em cámaras de frio sobre as propiedades físicas dos frutos foi também objecto de estudo
Impact testing in melon (Cucumis melo L.)
The application of Rheology to study biological systems is a new and very extensive matter, in which melon is absolutely unknown. The goal of this work is to determine some physical characteristics of this fruit, immediately after harvest and during its conservation in cold storage. Portugal and Spain are the most interested countries in these studies, as they are important producers of melon. The varieties Branco da Leziria and Piel de sapo were chosen because they are the most popular in both countries. The fruit were studied on the day they were harvested, and then were conserved in cold storage in the "Instituto del Frio" in Madrid, and they were periodically tested again. Thus during seven days the same fruits, and new fruits, were picked up and tested. On the first day of testing we had 20 fruits to study and at the end of the testing period we had used 80 fruits. The results from the non-destructive impact test were very significant and they may contribute to standardise methods to measure fruit maturity. These results were confirmed by those obtained from compression tests. The results obtained during the Impact tests with melon were similar to those obtained previously with other fruits. There is a close relationship between the results of the Impact tests and Compression tests. Tests like Impact and Compression can be adapted to melon, varieties 'Piel de Sapo" and 'Branco de Leziria', allowing us to continue further work with this species. The great number of data obtained during performance of the tests allowed us to go on with this work and to contribute to standardise methods of measurement and expression of characteristics of a new biological product. During the "Impact damage in fruits and vegetables" workshop, held in Zaragoza in 1990, these matters were included in the priority list
Storabelity of melon for different ripeness stages at harvest. Selection of instrumental procedures for quality assessment.
The consumption of melon (Cucumis melo L.) has been, until several years ago, regional, seasonal and without commercial interest. Recent commercial changes and world wide transportation have changed this situation. Melons from 3 different ripeness stages at harvest and 7 cold storage periods have been analysed by destructive and non destructive tests. Chemical, physical, mechanical (non destructive impact, compression, skin puncture and Magness- Taylor) and sensory tests were carried out in order to select the best test to assess quality and to determine the optimal ripeness stage at harvest. Analysis of variance and Principal Component Analysis were performed to study the data. The mechanical properties based on non-destructive Impact and Compression can be used to monitor cold storage evolution. They can also be used at harvest to segregate the highest ripeness stage (41 days after anthesis DAA) in relation to less ripe stages (34 and 28 DAA).Only 34 and 41 DAA reach a sensory evaluation above 50 in a scale from 0-100
The Role of Salt on Food and Human Health
Throughout time, salt (sodium chloride) played an important role in human societies. In ancient times, salt was used as a form of currency and to preserve foods, such as meat and fish. Besides, salt also assumed a major importance as food flavour enhancer. However, excessive salt consumption could result in serious health problems, related with hypertension and cardiovascular diseases, although this might be a controversial topic in the near future. The World Health Organization has made several policy recommendations to reduce salt intake and even implemented some policy approaches in several countries worldwide. Nevertheless, according to the European Food Safety Authority, approximately 75% of the salt we eat is already in the foods we buy. Thus, the best way to assure an effective reduction in salt consumption is to train our taste to the flavour of low-salt foods, although there is still a long way to go from awareness to action. The main goal of this chapter is to review the social and economic importance of salt throughout human history; its role in food preservation, food safety and food sensory evaluation; the impact of salt intake on human health; and the attempts to reduce or replace salt in food
Influence of the ripening stage on the quality of ‘Sweetheart’ cherry
The cherry is highly appreciated for its organoleptic and nutritional qualities, and for its important role in disease
prevention. The correct definition of the ripeness at harvest is indispensable for placing the cherry on the market
with high quality. Early harvesting, either for fear of rain or for immediate economic return, often occurs especially
at the beginning of the campaign. This study aims to evaluate the quality of ‘Sweetheart’ cherries at three stages of
ripeness (early ripeness, commercial ripeness, and advanced ripeness), to assist the producer in defining the ideal time
to harvest so that the fruit reaches the market with high quality. The results obtained suggest that the ‘Sweetheart’
cherry, at commercial ripeness, reaches values of firmness, soluble solids and acidity acceptable to the consumer.
However, cherries fully ripened on the tree show better nutritional quality, with higher values of antioxidant activity,
and phenolic compounds. For consumers to have cherries with high nutritional and sensory quality, the producer must
determine the optimal cherry harvest stage, to minimise quality losses and dispose of production quickly and in good
conditions, reducing waste
Table Grapes: There Is More to Vitiviniculture than Wine…
Table grapes are fruits intended for fresh human consumption due to their sensory attributes and nutritional value. The objective of this chapter is to review the existing knowledge about table grapes, including a description of different varieties, with particular emphasis on the new highly appreciated seedless varieties. Following an introductory note on the world distribution and production of table grapes, also considering the impact of climate change, selected varieties of table grapes will be characterized in terms of their physiology, postharvest features, and consumer preferences. A morphological description of each variety, with emphasis on grape skin, grape rachis and grape cluster will be included. A final note on the drying of table grapes into raisins, and the most appropriate varieties for drying, will be given. The major changes occurring throughout the growth, development, and ripening phases of table grapes production will be discussed, regarding both physical (skin color and skin and pulp texture) and chemical (phenolic compounds, sugar content and acidity) parameters, as well as growth regulators
Congresso nacional de recursos silvestres: livro de resumos
A criação do Centro de Competências dos Recursos Silvestres (CCRES) resultou do
reconhecimento da sociedade em geral e do poder político em particular de que existem
recursos no território nacional (cogumelos, medronho, figo-da-índia, e muitos outros)
aos quais deve ser dada maior atenção de forma a diversificar a atividade economia no
meio rural e a potenciar os efeitos favoráveis no funcionamento dos ecossistemas.
Associado à promoção da exploração económica destes recursos, é também necessário
assegurar que o seu uso é feito de forma sustentável, para não haver sobre-exploração
do recurso, como pode acontecer quando se faz colheita na natureza, como são exemplo
numerosos cogumelos silvestres.
Ao CCRES foi atribuída a missão de criar e promover as fileiras, assegurando uma ampla
partilha da informação disponível pelos agentes económicos, assegurando o
crescimento, a inovação, a internacionalização e a competitividade dos recursos
silvestres, como forma de aumentar a atividade económica nos territórios de baixa
densidade, tornando-os mais atrativos e com maior capacidade para fixar a população
jovem.
O Instituto Politécnico de Bragança (IPB) e a Universidade de Évora (UE), sobretudo
através dos seus centros de investigação CIMO (Centro de Investigação de Montanha) e
MED (Instituto Mediterrâneo para a Agricultura, Ambiente e Desenvolvimento),
respetivamente, são instituições com elevada atividade de investigação dirigida para os
territórios rurais e empenhadas em gerar conhecimento que facilite o aparecimento e a
expansão de negócios, bem como que os recursos silvestres seja usados de forma
sustentável.
O Congresso Nacional dos Recursos Silvestres (CNRS) resulta de uma iniciativa do CCRES,
promovida pela Associação de Defesa do Património de Mértola e financiada no âmbito
do PDR2020 (Operação - 20.2.4 - Assistência técnica RRN - Área 4 (Observação da
agricultura e dos territórios rurais) / Candidatura n.o - PDR2020-2024-080341). O IPB e
a UE são entidades parceiras corresponsáveis pela organização do evento, decorrendo
este em Bragança na Escola Superior Agrária do IPB.
O CNRS recebeu 51 comunicações, das quais 14 foram apresentadas na forma oral e as
demais como painel. O elevado número de comunicações recebidas e de participantes
inscritos demonstra o elevado interesse que Os Recursos Silvestres suscitam na
comunidade científica e na população em geral. Este livro de resumos terá, também ele,
um papel importante na difusão de conhecimento e da rede de entidades envolvidas
em atividades de investigação nestes setores, ajudando o CNRES a cumprir a sua missão.info:eu-repo/semantics/publishedVersio
Evaluation of the Potential of Opuntia Ficus-Indica Cladodes as a Natural Flocculant for Wastewater Treatment through Simple Procedures
Nowadays there is a search for new alternatives to replace harsh and expensive chemical methods to wastewater treatments. The common methods include the usage of chemicals that negatively affect the environment and the human health. The cladodes of Opuntia ficus-indica (L.) Mill have a great potential for use in innovative, cheap, renewable and eco-friendly water treatment due to their flocculant properties. In this work, different water treatments including fresh cladodes, lyophilized cladodes and the material obtained through mucilage extraction were tested. The turbidity of the water was measured, and it was concluded that the use of 60 g of small pieces of fresh cut cladodes was the method with the best results, reaching 4 NTU of turbidity. It confirmed the ability of O. ficus-indica (L.) Mill cladodes to promote the flocculation of clay in water, enabling to turn the unused material waste into a useful raw material
Segregation of soft olives using Durofel and on-line rebound
Traditional table olive fermentation processing produces variable proportions of defective olives that must be eliminated before final packaging. Defects include fish eye («alambradas»), compact («compactas») and over-ripe olives. For two testing periods during the 2001 season, different batches were graded by size, colour parameters, hardness, density and rebound distance (total number tested was 760 olives). The latter was determined using a specially designed prototype made by an on-line rotating drum covered with a commercial rubber material to avoid damage (13.3 cm total diameter and 6.81 rad s-1 rotation speed). Results showed that 96% of measured variance could be explained by the four Principal Components Analysis of extracted factors. Moreover, hardness measured as Durofel- 25 units is closely related to rebound distance. Softness thresholds have been addressed for both hardness parameters with devoted logistic models, permitting correct segregation (with 95% of well-classified individuals) of all soft olives (over-ripe and fish eye) using the rebound drum
Staphylococcus spp. and Lactobacillus sakei Starters with High Level of Inoculation and an Extended Fermentation Step Improve Safety of Fermented Sausages
ABSTRACT - Paio do Alentejo (PA) is one of the most popular dry-fermented sausages in Portugal.
The aim of the present work was to evaluate the effect of a high concentration of starter cultures
with an extended fermentation step on the safety and quality of PA. Physicochemical parameters,
microbiological parameters, biogenic amines, colour, texture profile, and sensory attributes were
assessed. Five starters were selected based on our previous works. Staphylococcus equorum S2M7,
Staphylococcus xylosus CECT7057, Lactobacillus sakei CV3C2, Lactobacillus sakei CECT7056, and a yeast
strain (2RB4) were co-inoculated in meat batters at a concentration of 108 cfu/g for bacteria and
106 cfu/g for yeast strain, and 0.25% dextrose was added. Inoculated starters significantly reduced
pH, Listeria monocytogenes counts, and total content in biogenic amines. The studied starter cultures
did not compromise the sensory characteristics of PA, and thus, their use can be considered to protect
these sausages and contribute to their safetyinfo:eu-repo/semantics/publishedVersio