The influence of the broccoli (Brassica oleracea var. itálica)fill weigth on postharvest quality

Broccoli is a vegetable of important economic value as well as a source of vitamin C and anticarcinogenic property substances. Although it can be minimally processed, this vegetable presents fast senescence, characterized by yellowing, loss of turgescence, development of off-odors, increase in enzymatic activity and reduction of nutritional value. Among the frequently used techniques that can extend the shelf-life of minimally processed broccoli, we have the use of cool storage and modified atmosphere packaging (MAP). Several factors interfere in the efficiency of MAP, influencing the speed and intensity of the changes on atmosphere composition. This work aimed to study the influence of the amount packaged broccoli on its postharvest quality, when stored at 1ºC. Results demonstrated strong influence of the use of MAP compared to control treatment. It was observed that for all packaged treatments there was better vitamin C retention, lower loss of weight, lower peroxidase activity and better turgidity score of broccoli. This study demonstrated that the treatments with higher amounts of product showed the worst performance on vitamin C and aroma evaluation. The peroxidase activity was also influenced, and the best results were found in the treatment with higher amounts, which presented lowest values. However there is a tendency of increase in the activity along the time, especially at the end of the experiment. It was not detected the influence of the fill weight about color evaluation.

Shelf life of minimally processed carrot and green pepper

The postharvest losses of horticultural products justify the use of preservation techniques. The processing not only adds value to the products, but also makes the products more convenient to the consumers. The objective of this research was to define the methodologies for the minimal processing of carrot and green pepper as to the type and intensity of the adoption of conservation techniques, and to monitor the products after processing through microbiological, physicochemical and nutritional analysis. The vegetables were washed and they were immersed in cold (7ºC) water with 100 mg L-1 free chlorine for sanitation, followed by centrifugation for 5 min. The product was put into BOPP/LDPE (biaxially orientated polypropylene/low-density polyethylene) plastic bags, which were sealed under atmospheric air, vacuum and modified atmosphere (2% O2, 10% CO2, 88% N2) and stored at 1ºC±1ºC. The approximate composition of the vegetables stayed stable during the storage period, in the three tested treatments. The contents of vitamin C for the samples of minimally processed carrot and green pepper did not present differences among treatments. The contents of beta-carotene decreased slightly during the storage period for the minimally processed carrot and green pepper. After processing, carrot and green pepper had psychrotrophic counts of 10²-10(5) and 10³-10(6) CFU g-1, respectively. Anaerobic mesophiles and total coliforms were found in green peppers, representing 1.6x10³ - 7.4x10(5) and <10.g-1 - 7.4x10(5), respectively. Total and fecal coliforms, anaerobic mesophiles and Salmonella were not found in carrots. Salmonella was not found in green pepper.

The Brazilian consumer's understanding and perceptions of organic vegetables: a Focus Group approach

Focus Group is a tool which generates, through interview sessions with a small number of participants, preliminary data to be used in subsequent quantitative stages. Many consumer studies use qualitative research with the aim of obtaining information and opinions on a specific product or situation. The objective of the present study was to obtain knowledge on the opinion, understanding and perception of the Brazilian consumer with respect to vegetables, focusing on organic products, using Focus Group Sessions. Four Focus Group Sessions were held with men and women in different environments, following a previously elaborated interview guide. In this study, it was observed that the consumers demonstrated being interested in having a healthy diet, based on fruit, vegetables and natural products. However, only a few declared consuming organic foods. Some participants did not know what the term organic meant, and most of them think that organic products are still very expensive, are not easily available in the supermarkets, do not have a good appearance, mainly in terms of size and packaging, and their certification is not always trustworthy. Almost all participants stated that they read package labels and among the items most observed were best-before date, nutritional information, production system and price. This study has identified important vegetable attributes perceived by the consumer, favouring the planning of a subsequent quantitative research. The results suggest that more information on the benefits of organic agriculture has to be passed on to consumers in order to contribute to a higher consumption of such products.

Informações nutricionais e de saúde disponibilizadas aos consumidores por restaurantes comerciais, tipo fast food e full service

O objetivo principal deste estudo foi identificar e caracterizar o oferecimento de informação nutricional e de saúde em restaurantes comerciais do município de Campinas-SP. Com a utilização de questionários previamente testados, foram entrevistados, entre outubro e dezembro de 2005, 20 gerentes de restaurantes do tipo fast food e 94 do tipo full service, localizados nas cinco regiões de Campinas. Após a coleta das informações, foi construído um banco de dados utilizando o software Excel. Para o tratamento estatístico, utilizou-se o teste do qui-quadrado e o teste T de Student. O software estatístico utilizado nas análises foi o MINITAB versão 14.2. Entre os principais resultados, destaca-se que 25,4% dos restaurantes fazem uso de informação nutricional e/ou de saúde. O tipo de informação nutricional mais empregado é a "declaração de nutrientes", com relevância para a informação do valor energético e de macronutrientes de alguns pratos. A fonte mais citada para a disposição da informação nutricional foi o cardápio, com 48,3% das citações. A freqüência de oferecimento dessas informações é significativamente maior entre as redes de fast food do que entre os restaurantes full service. Aponta-se a necessidade de se estudar formas de regulamentação dessas informações pelo poder público.

Influence of secondary packing on the freezing time of chiken meat in air blast freezing tunnels

Freezing of poultry cuts in continuous convective air blast tunnels is normally performed with the products protected by Low Density Polyethylene (LDPE) as a primary packaging and using Corrugated Cardboard Boxes (CCB) as secondary packaging. The objective of this work was to investigate the influence of these secondary packaging on the freezing of poultry cuts in continuous convective air blast tunnels. The study was performed by replacing CCB with Perforated Metal Boxes (PMB) in order to remove the packaging thermal resistance. The assays, performed in a industrial plant, demonstrated that CCB used commercially for meat freezing have a high heat transfer resistance. Their replacement with PMB can lead to shorter freezing times and spatially homogeneous freezing. Reductions of up to 45% in the freezing times were observed using PMB. The plateau of the temperature curve, related to the freezing time of free water, was significantly reduced using PMB, which is accepted to lead to better product quality after thawing. As the products were protected by the LDPE films as primary packaging, their appearance were not affected. The results presented in this work indicate that replacing CBB with PMB can be an excellent alternative to reduce freezing time and improve freezing homogeneity in industrial air blast tunnels, which could also be applied to other products.

Moisture adsorption characteristics of ginger slices

The moisture adsorption characteristics of dried ginger slices was studied to determine the effect of storage conditions on moisture adsorption for the purpose of shelf life prediction, selection of appropriate packaging materials, evaluate the goodness-of-fit of sorption models, and determine the thermodynamics of moisture adsorption for application in drying. There was a highly significant effect (p < 0.05) of water activity (a w), temperature, and pre-treatment on the equilibrium moisture content (EMC) of the dried ginger slices. At constant a w, the EMC decreased as temperature increased. The EMC of all samples increased as the a w increased at constant temperature. The sorbed moisture of the unpeeled ginger slices was higher than the peeled while those of unblanched samples were higher than the blanched. Henderson equation allows more accurate predictions about the isotherms with the lowest %RMS, and therefore, it describes best the adsorption data followed by GAB, Oswin, and Halsey models in that order. The monolayer moisture generally decreased with temperature for all samples. The isosteric heat decreased with moisture content approaching the asymptotic value or the latent heat of vaporization of pure water (∆Hst = 0) while the entropy of sorption was observed to increase with moisture content.

Quality of minimally processed guava with different types of cut, sanification and packing

The purpose of this project was to evaluate the sanitization effect on the quality of minimally processed guava. Initially, research was carried out with consumers in a supermarket to verify preferences of packaging for guava. Following this, the guava cv. Paluma underwent two sanitization sequences using dehydrated sodium dichloroisocyanurate compound, in 50 ppm concentration, sanitization prior to (S1) and after (S2) being cut; removal of excess water; conditioning in PET packaging and PSPVC and storage at 3 ºC ± 1 ºC. Physicochemical analysis - [pH, total soluble solids (SST), total labeled acidity (ATT), ascorbic acid (AA), total sugars (AT) and reducers (AR)], textural sensorial and microbiological analyses were used to monitor the quality of the products. The consumers preferred the guava cut in halves with pulp and packed in PET, although this packaging promoted condensation of water vapor on the inner surface of the lid, compromising the appearance of the product. The two sanitization sequences and the two kinds of packaging did not significantly affect the pH, SST, ATT, SST/ATT, texture and AA values. The AT and AR tenors increased significantly in the MP guavas stored in the PSPVC package. Both sanitizations were efficient in the bacterial control of the indicators of the hygienicsanitary conditions, although the S1 sanitization proved to be more efficient in the control of autochthonous aerobic microbiota (aerobic mesophylic microorganisms). It can be concluded that guava cv. Paluma packed in PSPVC can be conserved for 6 days when stored at 3 ºC.

Evaluation of temperatures in a refrigerated container for chilled and frozen food transport

The objective of this work was to monitor the operational conditions of the transport of chilled and frozen foods during delivery within cities and to evaluate the impact of the door openings on the alteration of the internal temperature of the refrigerated environment. Several temperature and pressure sensors were used in a refrigerated container with two compartments and they were installed in the refrigeration system unit and on the internal and external surfaces of the container. After the monitoring tests, it was verified that door openings during deliveries resulted in a disturbance that raised the internal temperature of the refrigerated container above values recommended for adequate conservation of the products transported. Moreover, increasing the number of door openings promoted a cumulative effect on the internal temperature, mainly in the chilled food compartment of the container. It was concluded that the refrigeration system unit presented serious limitations with regard to the maintenance of the container's internal temperature during the actual distribution routine, since it does not possess enough instantaneous capacity to restore the temperature set-point between deliveries.

Potential applications of nanotechnology in the agro-food sector

Nanoscience and nanotechnology are new frontiers of this century. Their application to the agriculture and food sectors is relatively recent compared with their use in drug delivery and pharmaceuticals. Smart delivery of nutrients, bioseparation of proteins, rapid sampling of biological and chemical contaminants, and nanoencapsulation of nutraceuticals are some of the emerging topics of nanotechnology for food and agriculture. In this review, some applications of nanotechnology in agro-food sector are discussed.

Inhibitory effect of the essential oil from Cinnamomum zeylanicum Blume leaves on some food-related bacteria

Cinnamomum zeylanicum Blume, Lauraceae, has long been known for having many biological properties. This study aimed to identify the constituents of the essential oil from C. zeylanicum leaves using GC-MS and to assess its inhibitory effect on Salmonella enterica, Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa based on MIC and MBC determination and kill-time study. Eugenol (73.27%) was the most prevalent compound in the essential oil followed by trans-β-cariophyllene (5.38%), linalool (3.31%), and alcohol cinamic acetate (2.53%). The results showed an interesting antibacterial activity of the oil with MIC ranging from 1.25 to 10 µL.mL-1. MBC values were in the range of 20 - 80 µL.mL-1. A concentration of 10 and 40 µL.mL-1 of the essential oil caused a fast and steady decrease in viable cell count (2 to 5 log cycles) of all assayed strains along 24 hours. A concentration of 40 µL.mL-1 of the oil provided a total elimination of the initial inocula of S. aureus after 2 hours. These results show the possibility of regarding the essential oil from C. zeylanicum leaves as alternative sources of antimicrobial compounds to be applied in food conservation systems.

Using Computational Fluid-Dynamics (CFD) for the evaluation of beer pasteurization: effect of orientation of cans

In-package pasteurization is the most used method for beer microbiological stabilization. The search for safer and better quality food has created a need to better understand the processes involved in producing it. However, little is known about the temperature and velocity profiles during the thermal processes of liquid foods in commercial packaging, which results in over-dimensioned processes to guarantee safety, decreasing the sensorial and nutritional characteristics of the product and increasing process costs. Simulations using Computational Fluid-Dynamics (CFD) have been used by various authors to evaluate those processes. The objective of the present paper was to evaluate the effect of packaging orientation in the pasteurization of beer in a commercial aluminum can using CFD. A heating process was simulated at 60 ºC up to 15 PUs (a conventional beer process, in which 1 Pasteurization Unit (PU) is equivalent to 1minute at 60 ºC). The temperature profile and convection current velocity along the process and the variation of the PUs were evaluated in relation to time considering the cans in the conventional, inverted, and horizontal positions. The temperature and velocity profiles were similar to those presented in the literature. The package position did not result in process improvement.

A method to determine volatile contaminants in polyethylene terephthalate (PET) packages by HDC-GC-FID and its application to post-consumer materials

A simple and low cost method to determine volatile contaminants in post-consumer recycled PET flakes was developed and validated by Headspace Dynamic Concentration and Gas Chromatography-Flame Ionization Detection (HDC-GC-FID). The analytical parameters evaluated by using surrogates include: correlation coefficient, detection limit, quantification limit, accuracy, intra-assay precision, and inter-assay precision. In order to compare the efficiency of the proposed method to recognized automated techniques, post-consumer PET packaging samples collected in Brazil were used. GC-MS was used to confirm the identity of the substances identified in the PET packaging. Some of the identified contaminants were estimated in the post-consumer material at concentrations higher than 220 ng.g-1. The findings in this work corroborate data available in the scientific literature pointing out the suitability of the proposed analytical method.

Effect of soaking and cooking on phytate concentration, minerals, and texture of food-type soybeans

The increasing consumption of soybeans due to its bioactive compounds has attracted interest in describing the grain's constituents and variation during processing. Phytate has been the aim of much research since it chelates essential minerals but also has beneficial antioxidant effects. This study evaluated the variation of phytate, calcium, zinc, and iron during soaking and cooking of soybeans. The phytate: Zn and phytate: Fe molar ratios were determined in order to estimate the bioavailability of these minerals. Six food-type varieties were used: BR 36, BRS 213, BRS 216, BRS 232, BRS 155, and Embrapa 48. The samples were soaked in water 3:1 (w/w) for 12 hours at room temperature and cooked. Cooking time was determined by modeling the softening of each variety using fractional conversion. Water content, phytate, and minerals were determined in raw, soaked and cooked samples. The water content of raw grains for all varieties was 9.9 g.100 g-1 increasing to a range of 58.1-63.7 g.100 g-1 after soaking and 63.1-66.0 g.100 g-1 after cooking. Soaking caused a significant reduction in phytate (23-30%), but cooking caused no additional reduction. The phytate: Zn molar ratio was 20 indicating that zinc absorption could be impaired, while the phytate: Fe molar ratio was 8, below the level of compromising absorption

Role of food safety in procedures adopted for the purchase of minimally processed and fresh vegetables by foodservices

This research was designed to analyze whether the procedures adopted by foodservice establishments for the purchase of minimally processed and fresh vegetables favor the acquisition of safe products. This research investigated the purchasing policies of such establishments, whether self-managed or administered by foodservice contractors, in the municipality of Campinas and its outlying districts. A random sample of thirty-nine establishments participated in the research. The instruments for data collection were pre-tested, and the actual interviews were conducted by trained personnel. Comparative analyses were made using various statistical tests. All of the participating establishments purchase fresh vegetables, although only six of them use minimally processed ones. For most of the establishments, price is at least one of the most important criteria for the selection of a supplier, and they do not normally monitor the safety of the fresh products purchased (51.3%), nor do they make regular technical visits to guarantee quality (46.2%); moreover, most do not carry out a supplier development program. It is suggested that routine technical visits to suppliers should be adopted, as well as the creation of courses, such as those dealing with the safety of vegetables and supplier development, to be offered to foodservices.

Influence of food components on lipid metabolism: scenarios and perspective on the control and prevention of dyslipidemias

Cardiovascular diseases (CVD) are the main causes of death in the Western world. Among the risk factors that are modifiable by diet, for reducing cardiovascular disease risks, the total plasma concentrations of cholesterol, triglycerides, LDL-C, and HDL-C are the most important. Dietary measures can balance these components of the lipid profile thus reducing the risk of cardiovascular diseases. The main food components that affect the lipid profile and can be modified by diet are the saturated and trans fats, unsaturated fats, cholesterol, phytosterols, plant protein, and soluble fiber. A wealth of evidence suggests that saturated and trans fats and cholesterol in the diet raise the total plasma cholesterol and LDL-C. Trans fats also reduce HDL-C, an important lipoprotein for mediating the reverse cholesterol transport. On the other hand, phytosterols, plant proteins, isoflavones, and soluble fiber are protective diet factors against cardiovascular diseases by modulating plasma lipoprotein levels. These food components at certain concentrations are able to reduce the total cholesterol, TG, and LDL-C and raise the plasma levels of HDL-C. Therefore, diet is an important tool for the prevention and control of cardiovascular diseases, and should be taken into account as a whole, i.e., not only the food components that modulate plasma concentrations of lipoproteins, but also the diet content of macro nutrients and micronutrients should be considered.