Microbiological quality and safety of minimally processed fruits in the marketplace of southern Portugal

The availability of fresh-cut fruit (FCF) in the marketplace has been increasing in Portugal, although reports of its microbial quality are not known. Due to the growing concerns of these commodities over their microbial safety, the objectives of this work were to study the microbiological quality and prevalence of Salmonella and Listeria monocytogenes on fresh-cut fruits sold in southern Portugal. A study to examine the changes in pH and microbial counts, before and after the expiration dates, was also made. A total of 160 samples was purchased in the local grocery stores between September 2011 and August 2014, before their sell-by date. These samples were assayed for aerobic mesophilic (AM) and psychrotrophic (AP) microorganisms, yeasts and molds (YM), lactic-acid bacteria (LAB), coliforms (TC), Escherichia coli and coagulase positive staphylococci as well as L. monocytogenes and Salmonella. The microbiological counts ranged from 3.0-9.2 lg cfu/g (AM); 2.2–10.7 lg cfu/g (AP); 2.3–10.4 lg cfu/g (YM); 1.9–9.0 lg cfu/g (LAB) and less than 1–9.1 lg cfu/g (TC). The melons and watermelon presented the highest levels of the microbial quality parameters studied. However, no E. coli, staphylococci, Salmonella and L. monocytogenes were detected in any of the samples. After the sell-by date, an increase of the AM, AP, LAB and YM values was observed in all fruits. Conversely, the differences found in TC counts before and after the best-before date had no statistical significance. A decrease in pH was observed in all fruits except pineapple whose pH slightly increased after 14 days of storage. The results highlight the importance of preventing contamination and cross contamination, selecting adequate decontamination technologies and maintaining a strict temperature control during processing, distribution and selling of FCF.

Impact Of Chemical Changes On The Sensory Characteristics Of Coffee Beans During Storage.

Sensory changes during the storage of coffee beans occur mainly due to lipid oxidation and are responsible for the loss of commercial value. This work aimed to verify how sensory changes of natural coffee and pulped natural coffee are related to the oxidative processes during 15 months of storage. During this period, changes in the content of free fatty acids (1.4-3.8 mg/g oil), TBARS values (8.8-10.2 nmol MDA/g), and carbonyl groups (2.6-3.5 nmol/mg of protein) occurred. The intensity of rested coffee flavour in the coffee brew increased (2.1-6.7) and 5-caffeoylquinic acid concentration decreased (5.2-4.6g/100g). Losses were also observed in seed viability, colour of the beans and cellular structure. All the results of the chemical analyses are coherent with the oxidative process that occurred in the grains during storage. Therefore, oxidation would be also responsible for the loss of cellular structure, seed viability and sensory changes.

S-nitrosothiols Regulate Nitric Oxide Production And Storage In Plants Through The Nitrogen Assimilation Pathway.

Nitrogen assimilation plays a vital role in plant metabolism. Assimilation of nitrate, the primary source of nitrogen in soil, is linked to the generation of the redox signal nitric oxide (NO). An important mechanism by which NO regulates plant development and stress responses is through S-nitrosylation, that is, covalent attachment of NO to cysteine residues to form S-nitrosothiols (SNO). Despite the importance of nitrogen assimilation and NO signalling, it remains largely unknown how these pathways are interconnected. Here we show that SNO signalling suppresses both nitrate uptake and reduction by transporters and reductases, respectively, to fine tune nitrate homeostasis. Moreover, NO derived from nitrate assimilation suppresses the redox enzyme S-nitrosoglutathione Reductase 1 (GSNOR1) by S-nitrosylation, preventing scavenging of S-nitrosoglutathione, a major cellular bio-reservoir of NO. Hence, our data demonstrates that (S)NO controls its own generation and scavenging by modulating nitrate assimilation and GSNOR1 activity.

Preparation Of An Agar-silver Nanoparticles (a-agnp) Film For Increasing The Shelf-life Of Fruits.

Preparation of protective coating possessing antimicrobial properties is present day need as they increase the shelf life of fruits and vegetables. In the present study, preparation of agar-silver nanoparticle film for increasing the shelf life of fruits is reported. Silver nanoparticles (Ag-NPs) biosynthesised using an extract of Ocimum sanctum leaves, were mixed with agar-agar to prepare an agar-silver nanoparticles (A-AgNp) film. This film was surface-coated over the fruits, Citrus aurantifolium (Thornless lime) and Pyrus malus (Apple), and evaluated for the determination of antimicrobial activity of A-AgNp films using disc diffusion method, weight loss and shelf life of fruits. This study demonstrates that these A-AgNp films possess antimicrobial activity and also increase the shelf life of fruits.

Anthocyanin And Other Phenolic Compounds In Ceylon Gooseberry (dovyalis Hebecarpa) Fruits.

Ceylon gooseberry is a deep-purple exotic berry that is being produced in Brazil with great market potential. This work aimed to determine major phenolic compounds in this specie by HPLC-PDA-ESI/MS. Samples were collected in two different seasons. Pulp and skin were analyzed separately. Non-acylated rutinoside derivatives of delphinidin (∼60-63%) and cyanidin (∼17-21%) were major anthocyanins tentatively identified. All anthocyanins had higher concentration in skin than in pulp (64-82 and 646-534mg of cyaniding-3-glucoside equivalents/100g skin and pulp, respectively). Moreover, anthocyanin profile changed between sampling dates (p<0.05). Mainly for delphinidin-3-rutinoside which could be a result of season variation. In this specie, non-anthocyanin polyphenols represent less than 35% of total extracted polyphenols. The tentative identification proposed a flavonol and three ellagitannins as major compounds of the non-anthocyanin phenolics fraction. Finally, anthocyanin is the major phenolic class in this fruit and its composition and content are significantly affected by season.

Determination Of The Phenolic Composition From Brazilian Tropical Fruits By Uhplc-ms/ms.

Although Brazil is the third largest fruit producer in the world, several specimens consumed are not well studied from the chemical viewpoint, especially for quantitative analysis. For this reason and the crescent employment of mass spectrometry (MS) techniques in food science we selected twenty-two phenolic compounds with important biological activities and developed an ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) method using electrospray (ESI) in negative ion mode aiming their quantification in largely consumed Brazilian fruits (açaí-do-Amazonas, acerola, cashew apple, camu-camu, pineapple and taperebá). Multiple reaction monitoring (MRM) was applied and the selection of proper product ions for each transition assured high selectivity. Linearity (0.995-333.3pg/mL), limit of quantification (96.15-1111pg/mL), inter- and intraday accuracy (>80%), precision (CV<20%) and extraction recovery rate (>80%) were satisfactory and showed that the method provides an efficient protocol to analyze phenolic compounds in fruit pulp extracts.

Avaliação física do tomate de mesa 'Romana' durante manuseio na pós-colheita

Tomato postharvest losses are very high in Brazil and the goal of this research was to evaluate the effect of handling and the transport of tomato fruits, cultivar Romana on the steps of harvesting, weight and transportation to the packinghouse, pointing some critical points. Tomatoes were harvested at plastic boxes, weighted and shipped to a packinghouse. Fruits taken directly from the plant were determined as reference. The parameters evaluated were weight loss and mechanical injury and tomato physical quality after storage during 21 days. It was observed an increasing on the weight loss, external damage, and postharvest losses, after storage. Handling and transportation were the cause of an increase in 6.6% in external damage and 1.93% of weight loss after storage, when comparing harvested fruits and fruits evaluated on the packing-house. The main reason for postharvest losses was due to mechanical injury caused during transportation mainly due to the compressure force among fruits and against the plastic boxes.

Utilização de 1-metilciclopropeno e resfriamento rápido na conservação de pêssegos

Postharvest losses vary among the different vegetable products. However, among fruits and vegetables the losses generally range from 30% to 50%. Thus, this paper aimed the application of 1-methylcycloprene (1-MCP) and fast cooling with forced air (PC) on peaches, in order to estimate their effects in the ripening process of this fruit. Physiological analyses were performed, such as loss of fresh mass, firmness, pH, titratable acidity, soluble solids, ratio and CO2 production, as well as sensorial analyses such as color, texture and flavor. The experiment was divided in two phases. In the first one, concentrations of 30, 60, and 90 nL/L 1-MCP, applied at 0 ºC and 20 ºC, were tested. The fruits treated without 1-MCP were denominated control for both temperatures studied. The second phase was composed by the following treatments: cold storage (CS) or control, cooling with forced air (CFA), cooling with forced air followed by 1-MCP application (CFA + 1-MCP) and 1-MCP application (1-MCP). Among these, the CFA + 1-MCP treatment provided more firmness of the fruits in comparison to the control fruits. The respiratory rate of peaches under CFA and CFA + 1-MCP treatments decreased in comparison to the control fruit respiratory rates.

Avaliação de linhas de beneficiamento e impactos de queda na qualidade de caqui Rama Forte

Excessive and inadequate handling of fruits and vegetables provides high incidences of physical damage, consequently, post harvest losses. The main goal of this work was to evaluate the impact magnitude in persimmon packing lines, Rama Forte, and to determine, at the laboratory, its impact limits. For evaluating the critical points it was used an instrumented sphere of 76 mm of diameter (Technmark, Inc, Lansing, USA), which registered the impact magnitude in seven distinctive impact lines located in four packing houses. For determining physical damages, tests were carried out at the laboratory, where fruit drop was related to impact magnitude, physical damage incidence and fruit post harvest losses. At the packing lines, the values found varied from 21 to 87 G on the transfer points and the majority of registered impacts (over 94%) were down 50G. Drops from 20 cm caused an increase in weight losses after six days of storage at room temperature. Drops from 20 and 30 cm caused skin darkness (low L values), associated to a decrease in color intensity (chroma). Impact drop did not affect pulp fruit chemical features.

Qualidade pós-colheita de caqui 'fuyu' com utilização de diferentes concentrações de cobertura comestível

One of the main objectives of applying edible coatings on fruits surface is to create a protective film to reduce weight loss due to evaporation and transpiration and also to decrease the risk of fruit rot caused by environmental contamination, in order to improve the visual aspect. Therefore, it is possible to increase shelf life, and decrease post harvest losses. Persimmon is a much appreciated fruit, with high potential for export, but sensitive to handling and storage. This study aimed to evaluate the effect of applying the edible coating Megh Wax ECF-124 (18% of active composts, consisting of emulsion of carnauba wax, anionic surfactant, preservative and water) produced by Megh Industry and Commerce Ltda in three different concentrations (25, 50 and 100%) on post harvest quality of 'Fuyu' persimmon stored for 14 days. The attributes evaluated for quality were: firmness, pH, acidity, soluble solids, weight loss and color. The results showed that application of carnauba wax in different concentrations was effective on decreasing weight loss of persimmon cv. Fuyu and maintenance of color aspects. Treatment at lower concentration, 25%, showed lower rate of discharge, but high concentrations showed lower values of mass loss. Carnauba wax application showed a high potential for use on postharvest conservation, and can be applied together with other technologies, helping to maintain quality for export.

Effect of cement type and water storage time on the push-out bond strength of a glass fiber post

This study investigated the effects of the cement type and the water storage time on the push-out bond strength of a glass fiber post. Glass fiber posts (Fibrekor, Jeneric Pentron) were luted to post spaces using a self-cured resin cement (C&B Cement [CB]), a glass ionomer cement (Ketac Cem [KC]) or a resin-modified glass ionomer cement (GC FujiCEM [FC]) according to the manufacturers’ instructions. For each luting agent, the specimens were exposed to one of the following water storage times (n=5): 1 day (T1), 7 days (T7), 90 days (T90) and 180 days (T180). Push-out tests were performed after the storage times. Control specimens were not exposed to water storage, but subjected to the push-out test 10 min after post cementation. Data (in MPa) were analyzed by Kruskal-Wallis and Dunn`s test (α=0.05). Cement type and water storage time had a significant effect (p<0.05) on the push-out bond strength. CB showed significantly higher values of retention (p<0.05) than KC and FC, irrespective of the water storage time. Water storage increased significantly the push-out bond strength in T7 and T90, regardless of the cement type (p<0.05). The results showed that fiber posts luted to post spaces with the self-cured resin cement exhibited the best bonding performance throughout the 180-day water storage period. All cements exhibited a tendency to increase the bond strength after 7 and 90 days of water storage, decreasing thereafter.

Quality of sausage elaborated using minced Nile Tilapia submmitted to cold storage

Filleting yield of Nile tilapia Oreochromis niloticus (L.) is low (30%) and generates large amount of wastes that may turn into environmental and economic problem. However, these wastes can be used for the extraction of minced fish (MF) which can be used in the preparation of sausages. The objective of this study was to assess the quality of sausages prepared with 0, 20, 40, 60, 80 and 100% of MF from Nile tilapia filleting waste during storage at 0±0.3ºC. Alterations in the instrumental color (L*, a* and b*), lipid oxidation (TBARS), total volatile nitrogenous bases (TVB-N), pH, microbiological condition (pathogenic bacteria and aerobic psychrotrophic bacteria), and sensory attributes (color, odor, flavor, texture and overall acceptability) were evaluated for up to 40 days. The addition of MF to sausages increased TBARS values and decreases TVB-N, L*, a* and b* values. Acceptability of color attribute decreased with increasing MF; best flavor, texture and overall acceptability scores were registered for sausages containing 40 and 60% MF; best odor was registered for 100% MF. Pathogenic microorganisms were not detected, but decrease in pH and proliferation of aerobic psychrotrophic bacteria which, however, did not compromise sensory evaluation of sausages were registered throughout storage. Sausages prepared with MF from tilapia filleting waste have a shelf-life of 40 days when stored at 0±0.3ºC, and the maximum recommended MF inclusion to maintain good sensory quality is 60%.

Stability of fruit bases and chocolate fillings

Syrups with high sugar content and dehydrated fruits in its composition can be added to chocolate fillings to reduce the need of artificial flavor and dyes attributing a natural appeal to the product. Fruit bases were produced with lyophilized strawberry, passion fruit, and sliced orange peel. Rheological dynamic oscillatory tests were applied to determine the products stability and tendency of shelf life. Values of G´< G´´ were observed for strawberry and passion fruit flavor, whereas values of G´ > G´´ were found for orange flavor during the 90 days of storage. It was observed that shear stress values did not vary significantly suggesting product stability during the studied period. For all fillings, it was found a behavior similar to the fruit base indicating that it has great influence on the filling behavior and its stability. The use of a sugar matrix in fillings provided good shelf life for the fruit base, which could be kept under room temperature conditions for a period as long as one year. The good stability and storage conditions allow the use of fruit base for handmade products as well as for industrialized products.

Validation of a food frequency questionnaire to assess the consumption of carotenoids, fruits and vegetables among adolescents: the method of triads

The aim of this study was to validate the intake of carotenoids, fruits and vegetables estimated by the Food Frequency Questionnaire for Adolescents (FFQA) using the method of triads. Blood samples were collected from 80 elementary school adolescents to assess serum levels of β-carotene. Partial correlation coefficients (r) were calculated between an estimated intake of carotenoids, fruits and vegetables and the serum levels of β-carotene. Validity coefficients were calculated using the method of triads. With the exception of carotenoids, partial r from the food frequency questionnaire (FFQ) were greater than those of the 24-hour recall (24hR). The fruit/vegetable group showed the highest partial r for the FFQ (r = 0.235) and the 24hR (r = 0.137). The highest validity coefficient was obtained for the vegetable group, as assessed by the FFQ (r = 0.873). On average, the validity coefficient values for the FFQ were greater than those obtained for the 24hR or the β-carotene serum levels. The FFQA is an accurate tool for estimating the intake of carotenoids, fruits and vegetables in this population group.

Discrepancies among ecological, household, and individual data on fruits and vegetables consumption in Brazil

Information on fruits and vegetables consumption in Brazil in the three levels of dietary data was analyzed and compared. Data about national supply came from Food Balance Sheets compiled by the FAO; household availability information was obtained from the Brazilian National Household Budget Survey (HBS); and actual intake information came from a large individual dietary intake survey that was representative of the adult population of São Paulo city. All sources of information were collected between 2002 and 2003. A subset of the HBS, representative of São Paulo city, was used in our analysis in order to improve the quality of the comparison with actual intake data. The ratio of national supply to household availability of fruits and vegetables was 2.6 while the ratio of national supply to actual intake was 4.0. The discrepancy ratio in the comparison between household availability and actual intake was smaller, 1.6. While the use of supply and availability data has advantages, as lower cost, must be taken into account that these sources tend to overestimate actual intake of fruits and vegetables.