Low Density Polyethylene Bags Research Articles

Fruit characteristics and cuticle triterpenes as related to postharvest quality of highbush blueberries

Chilean fresh blueberries take 20–50days to arrive by boat to the Northern hemisphere, softening and dehydration being the main defects upon arrival. The effect of maturity at harvest (75% blue, 100% blue, and overripe) on cuticular triterpene content, and the possible associated impacts on firmness and weight loss after cold storage were explored for ‘Duke’ and ‘Brigitta’ fruit, both non-bagged or bagged in macro-perforated low-density polyethylene bags. Softening and weight loss varied with cultivar and maturity stage: ‘Duke’ fruit softened faster and were more prone to dehydration than ‘Brigitta’ samples, whereas overripe fruit were less firm after storage. This is the first report characterizing the triterpenoid fraction in cuticles of fresh blueberries, which may play a role in their postharvest behavior. Weight loss and softening rates were highly correlated to ursolic acid contents at harvest; further research will be required for a better understanding of these relationships.

Calidad y cambios microbiológicos en calabaza mínimamente procesada y empacada en polietileno de baja densidad

La calabaza (Cucurbita moschata) mínimamente procesada tiene un potencial considerable para crear nuevas oportunidades en el mercado de valor agregado en Puerto Rico. El objetivo de este trabajo fue evaluar la calidad y microbiología de la calabaza tropical mínimamente procesada empacada en bolsas de polietileno de baja densidad (LDPE, por sus siglas en inglés) y almacenada durante 20 días. Pedazos de 2 cm3 de dos cultivares de calabaza ('Taina Dorada' y 'Soler') fueron tratados por inmersión con una solución antimicrobiana que contenía ácido cítrico (0.2%) y benzoato de sodio (0.1%) durante 3 min, centrifugados en una hilandera de ensaladas, empacados en bolsas de LDPE, sellados al vacío y sin vacío, y almacenados a 4° C ± 2 durante un período de 20 días. El tiempo de almacenamiento tuvo un efecto mínimo sobre las características químicas y físicas de los pedazos de calabaza. El contenido de O2 en los empaques sellados sin vacío disminuyó, mientras que el contenido de CO2 tuvo un incremento en las primeras 72 horas de almacenamiento. Los jurados del panel sensorial determinaron que la calabaza almacenada por 20 días mantiene una calidad aceptable. El producto mínimamente procesado tratado con una solución antimicrobial, empacado en bolsas de LDPE (selladas al vacío o sin vacío) y almacenado por 20 días a 4° C ± 2 presentó niveles microbiológicos seguros y una calidad aceptable por el consumidor.

Effect of Packaging on Shelf-life and Lutein Content of Marigold (Tagetes erecta L.) Flowers.

African marigold (Tagetes erecta L.) flowers are highly valued for their ornamental appeal as well as medicinal properties. However, their short shelf lives cause high post-harvest loss and limit their export potential. The review of patents and research articles revealed that different types of packaging designs/materials have been successfully employed for extension of shelf lives of cut flowers. The current work focuses on designing of different packaging configurations and selection of best configuration for preservation of marigold cut flowers. Ten packaging configurations, composed of four different packaging materials i.e., low density polyethylene (LDPE), polyethylene terephthalate, glassine paper and cellophane paper, were designed. Each pack, consisting of 20 ± 1 g of marigold flowers along with non-packaged control set were stored at 23 ± 2°C, 80% R.H., in an environmental chamber and the flowers were evaluated for their sensory attributes, phytochemical characteristics and physicochemical parameters of senescence to determine their shelf lives. Flowers packed in LDPE bag showed highest shelf life of 8 days with a lead of 4 days compared to control (shelf life - 4 days). This study also established for the first time the phenomenon of carotenogenesis in marigold cut flowers with significantly (P<0.01) higher production of lutein in LDPE packaged flowers. LDPE pack was the best design among the ten package designs, in preserving lutein content of marigold flowers and extending their shelf lives. This economically viable packaging can not only boost the export potential of this ornamental flower, but also allow utilization of nutraceutical potency of lutein.

Respiration and ethylene generation modeling of “Hass” avocado and feijoa fruits and application in modified atmosphere packaging

ABSTRACTA proper description of the respiration and ethylene generation is important in the development of package systems for the preservation of fresh fruits and vegetables. In this work, a model based on both Michaelis-Menten and chemical kinetics equations was developed and assessed in order to describe the respiration and ethylene generation of avocado (Persea americana cv. Hass) and feijoa fruits (Acca sellowiana Berg) from experimental data obtained at different temperatures by a closed system method. The temperature effect in both processes was described using Arrhenius-type relationships. After this, avocadoes and feijoas were packed in perforated low-density polyethylene (LDPE) and polypropylene (PP) bags for 8 days at 12°C and 80% RH to validate the usefulness of the model to describe the gas evolution in modified atmosphere packaging (MAP). For avocado fruits, respiration rates of 2680-3030 cm3 kg-1 d-1 were obtained at 24 °C and normal atmosphere, and 3650-4230 cm3 kg-1 d-1 for feijoa fruits. As for ethylene production rates, at 24 °C were obtained values of 3.11 cm3 kg-1 d-1 for avocado and 0.50 cm3 kg-1 d-1 for feijoa. At 6 °C, respiration and ethylene production rates were up to 6 times lower. It was possible to describe properly the ethylene generation using a Michaelis-Menten simple equation and the respiration rates using a Michaelis-Menten uncompetitive kinetics for both fruits with coefficients of determination above 0.9 in each case. The overall model was validated in the MAP test being possible to predict successfully the O2, CO2 and C2H4 levels inside the packages.

English

Fresh fruits and vegetables are inherently more liable to deterioration under tropical conditions characterized by high ambient temperatures and humidity. In determining the effects of chemical treatment on tomatoes (Lycopersicon esculentum Mill cv. Roma), fruits purchased at turning stage of ripening were packaged in low density polyethylene bags (60 µ) containing wooden dust particles moistened with 400 ppm potassium permanganate solution. Samples were treated with hot water dip, boric acid (H₃BO₃) dip at 1000 ppm, CaCl₂ dip at 10,000 ppm, a combination of H₃BO₃ and calcium chloride treatment as well as control. Results of chemical treatment showed increase in weight loss, pH, and a slight increase in moisture content. Total soluble solids and titratable acidity of samples showed a steady decrease, with data on physicochemical qualities collected at 7 days interval. Fruits stored with hot water and combination of H₃BO₃ and CaCl₂ treatments showed higher keeping quality. Shelf life elongation treatments used at tropical ambient temperature of 30 ± 2°C was able to preserve tomato fruits for 21 days from spoilage and microbial attack while retaining its colour and other physicochemical properties. Key words: Tomato, shelf life, packaging, respiration, pretreatment.

Waste flow analysis and life cycle assessment of integrated waste management systems as planning tools: Application to optimise the system of the City of Bologna.

The results of this case study are used to argue that waste management planning should follow a detailed process, adequately confronting the complexity of the waste management problems and the specificity of each urban area and of regional/national situations. To support the development or completion of integrated waste management systems, this article proposes a planning method based on: (1) the detailed analysis of waste flows and (2) the application of a life cycle assessment to compare alternative scenarios and optimise solutions. The evolution of the City of Bologna waste management system is used to show how this approach can be applied to assess which elements improve environmental performance. The assessment of the contribution of each waste management phase in the Bologna integrated waste management system has proven that the changes applied from 2013 to 2017 result in a significant improvement of the environmental performance mainly as a consequence of the optimised integration between materials and energy recovery: Global Warming Potential at 100 years (GWP100) diminishes from 21,949 to -11,169 t CO2-eq y(-1) and abiotic resources depletion from -403 to -520 t antimony-eq. y(-1) This study analyses at great detail the collection phase. Outcomes provide specific operational recommendations to policy makers, showing the: (a) relevance of the choice of the materials forming the bags for 'door to door' collection (for non-recycled low-density polyethylene bags 22 kg CO2-eq (tonne of waste)(-1)); (b) relatively low environmental impacts associated with underground tanks (3.9 kg CO2-eq (tonne of waste)(-1)); (c) relatively low impact of big street containers with respect to plastic bags (2.6 kg CO2-eq. (tonne of waste)(-1)).

Suitability of Partial Replacement of Pulverized Plastic as Fine Aggegate in Cement Concrete

Objectives: Disposal of plastic was a major problem in the present era, as the usage of plastics was growing day by day and it takes hundreds of year for plastic material to degrade. The effective ways to recycle and reuse of plastics are being formulated. Methods: Low Density Polyethylene (LDPE) Bags was taken into consideration as it was easily available and had low density than other type. The used plastic bags were collected, ground in to smaller components. Melted and pulverized in order to get granules of plastic of about 1 mm size. The density of the pulverized was found to be 920 Kg/m³ and its specific gravity was 0.89. Seive analysis were carried out and about 95% of the plastic bags were found to be in the range of 1-1.15 mm. 45 Nos of 100 × 100 × 100 mm cement concrete cubes of M20 mix were cast for 0%, 5%, 10%, 15% and 20% fine aggregate being replaced with pulverized plastic material. Volumetric proportioning was adopted instead of design mix since the low density of plastic bags material was too low. Workability test, mechanical properties were determined. Findings: The test results revealed that the compression strength of concrete at 28th days of conventional concrete is 23.56 N/mm². By partial replacement of 5% of Burned LDPE bags in concrete the 28th days increased by about 0.36 N/mm² when compared to conventional concrete. By partial replacement of 10% of burned LDPE bags in concrete the 28th days increased by about 1.02 N/mm² when compared to conventional concrete. By partial replacement of 15% of burned LDPE bags in concrete at 28th day increased by about 2.27 N/mm² for when compared to conventional concrete. By partial replacement of 20% of Burned LDPE bags in concrete the 28th days increased by about 1.16 N/mm² when compared to conventional concrete. Thus it is inferred that partial replacement of Burned LDPE bags up to 15% can be adopted. Novelty/Improvement: It is thereby suggested that utilization of this Low Density Polyethylene (LDPE) bags in concrete will reduce the requirement for convectional fine aggregate thereby resulting in conservation of natural resources.

Anaesthetic efficacy of clove oil-coated LDPE bag on improving water quality and survival in the Siamese fighting fish, Betta splendens, during transportation

With brilliant colouration and long, flowing fins, the Siamese fighting fish (Betta splendens) is one of the most popular species of freshwater aquarium fish. In the ornamental Siamese fighting fish business, stress is one of the major causes of fish injury, including collapse of the fins. To overcome this problem, attempts are being made to develop anaesthetic packaging, in which anaesthetic agents are coated onto low-density polyethylene (LDPE) packaging bags and released from the bags. The feasibility of using clove oil-incorporated methylcellulose-coated LDPE bag as a packaging material to induce an anaesthetic effect on Siamese fighting fish during transportation was also investigated. Based on a criterion of fish transportation within 2 days, concentrations of clove oil in anaesthetic-coated LDPE bag ranging from 0 to 11.67 mg L−1 were determined using an aqueous dilution method. Clove oil-incorporated methylcellulose-coated LDPE bags, filled with either 150 or 75 mL water and with equivalent anaesthetic concentrations, induced an anaesthetic effect in a similar manner. After 48 h of fish exposure, the water quality in clove oil-incorporated methylcellulose-coated LDPE bags was better than that of the control treatment. This study demonstrated that clove oil-incorporated methylcellulose-coated LDPE packaging bag could be successfully employed for transportation of Siamese fighting fish; in turn, this will minimize a dropped price when reaching the destination.

Effect of sulfur dioxide and modified atmosphere packaging on blueberry postharvest quality

Sulfur dioxide and modified atmospheres were evaluated to find the optimal method to control decay and prolong the quality of blueberries after harvest. To determine the most suitable MAP system for highbush blueberry (Vaccinium corymbosum, ‘Brigitta’), fruit were stored in controlled atmospheres (CO2/O2 partial pressures in kPa: 5/1; 7/15, 15/5) or an atmosphere modified by varying the amount of fruit in two modified atmosphere packaging (MAP) systems. The MAP systems employed bags with 60μm-thick low density polyethylene where the fruit were hermetically sealed in the bag: (1) without perforation (MAP 0); or (2) with two perforations of 3mm2 (MAP 2). ‘O’Neal’, ‘Duke’, ‘Legacy’, ‘Brigitta’, ‘Elliott’ and ‘Aurora’ were evaluated to reduce deterioration by the most suitable MAP system and, in a separate experiment, ‘Legacy’ fruit were fumigated with SO2 and packed in the MAP and compared with perforated bag (PB). The effectiveness of reducing blueberry deterioration was evaluated after 30–45days at 0°C. CO2 partial pressure higher than 8kPa or O2 partial pressure lower than 2kPa induces ‘Brigitta’ fruit softening. Among the evaluated cultivars, MAP 2 attained CO2 and O2 partial pressures between 4.5–6.0kPa and 13–15.0kPa, respectively. Induction of fruit softening by CO2 was dependent on the cultivar. ‘O’Neal’, ‘Duke’ and ‘Legacy’ were extremely sensitive, at CO2 concentration of 6kPa. The benefits of MAP 2 were mainly attributed to humid environment within the packages that allow reducing weight loss and symptoms of dehydration; effects that were mimicked by the perforated bag. ‘Legacy’ blueberry fruit were fumigated for 30min at 20°C with SO2 at concentration time product of 100–150 (μLL−1) h, followed by packaging in MAP 2 or in a perforated (0.3% ventilation area) low density polyethylene bag and storage for 45days at 0°C. Decay, weight loss, and the percentage of dehydrated and soft fruit were reduced effectively when the SO2-fumigated fruit were stored in either MAP 2 or the perforated bag. Decay was particularly well controlled by SO2. SO2 fumigated fruit, packed into a perforated bag was a better option than packaging the fruit into modified atmosphere bags, where the CO2 steady state partial pressure that controlled decay was extremely close to the level that injured the fruit.

Modified atmosphere packaging effects on the postharvest quality of papaya fruit

Export of Fijian papaya (Carica papaya) fruit to destinations such as New Zealand has increased significantly over the last several years. Shipment by sea rather than air is the preferred method, given the capacity for larger volumes and reductions in cost. Long shipping times, however, can compromise fruit quality, although the use of modified atmosphere packaging (MAP) may provide a viable solution for extending fruit storage life. In a collaborative ACIAR project, Australian and Fijian researchers investigated the potential of using MAP to extend storage life of a Fijian papaya ('Fiji Red') fruit based on simulated sea transport conditions. Fruit were packed in one of three MAP environments within cartons, consisting of either a (1) Low Density Polyethylene (LDPE) bag with 10 g of KMnO4, (2) Polyamide Film (PF) bag with macro-perforations or (3) without a bag (control fruit). Fruit were held for 1, 2 or 3 weeks at 10°C before being unpacked, ripened and assessed for quality. On day 6 after outturn, fruit with the highest overall quality were those held in LDPE bags. LDPE fruit generally coloured up faster at outturn than PF or control fruit, had less overall moisture loss and scored high in flavour. Headspace carbon dioxide and oxygen concentrations within the LDPE bags were also near recommended levels for maintaining optimum storage-life quality. The LDPE bag provided the most suitable conditions for long term storage of fresh papaya fruit and is therefore the recommended MAP type for use with sea freight export out of Fiji.

Storage Stability of Mutton Nuggets Extended with Carrot Powder as A Functional Ingredient

A study was conducted to evaluate the storage stability of mutton nuggets extended with 2% carrot powder against control with no carrot powder. The product was packed in low density polyethylene bags, stored at 4±1°C and evaluated at 5 day intervals for 25 days for various physico-chemical, microbiological and sensory quality attributes. The pH of the nuggets increased significantly (P<0.05) during storage, but the increase was lower in carrot powder extended nuggets (6.44) than control (6.55). Overall thiobarbituric acid reactive substances (TBARS) of mutton nuggets extended with carrot powder (0.22 mg malonaldehyde/kg) was significantly (P<0.05) lower than control (0.37 mg malonaldehyde/kg). Total plate count of control (2.84 log10 cfu/g) was higher than carrot powder extended mutton nuggets (2.72 log 10 cfu/g). Psychrotrophs showed growth after 15 days whereas yeast and mould showed growth after 20 days, but psychrotroph, yeast and mould counts of carrot powder extended with mutton nuggets were lower than control. The overall sensory quality of carrot powder extended with mutton nuggets was higher than control. It was concluded that the overall storage stability of mutton nuggets extended with carrot powder was better than control.

Toughening and its association with the postharvest quality of king oyster mushroom (Pleurotus eryngii) stored at low temperature

Toughening-induced textural decay easily occurs in stored mushrooms. The objective of this study was to investigate the textural alteration caused by toughening in relation to other quality attributes of king oyster mushroom (Pleurotus eryngii). Fresh king oyster mushrooms, packed in low-density polyethylene bags, were stored at different low temperatures for 18days to measure textural and other quality attributes. It was found that toughening occurred twice during the entire storage time. Highly associated change profiles were observed for the lignin content and activities of three important enzymes involved in lignin synthesis. The chitin and cellulose contents exhibited low correlation with toughening. Malondialdehyde content, electrolyte leakage rate and total phenolics content appeared to be related to toughening, but the browning index showed a negative correlation with toughening. Our results suggested that toughening may be mainly caused by lignification and can affect the postharvest quality of the tested mushrooms.

Effect of Film Packaging on the Quality of Tomato Fruits under Ambient Conditions

Polyethylene bags of different permeability were tested to extend the life of tomatoes (Lycopersicon esculentum) under ambient conditions. Tomato fruits at Breaker stage of ripening were packed in low density polyethylene bags (thickness 0.0046 mm) with four different types of perforation, i.e. without pinholes, bag with 10, 15 and 20 pinholes. All bags were stored for 21 days at 28ºC and 74% relative humidity. Fruits were evaluated for changes in colour, physical appearance, firmness and weight loss. Soluble solids content was determined at the end of storage. All unwrapped tomato fruits were red ripe 6 days after storage and after 21 days of storage fruits were soft, appeared deep red, shriveled and dusty. Fruits sealed in bags delayed red colour development, appeared glossy after 21 days of storage. Fruits sealed in polyethylene bags were significantly (p&lt;0.05) firmer and had low weight loss than fruits stored unwrapped. Fruits sealed within polyethylene bag with 20 pinholes had the highest soluble solids content after 21 days. This study shows that storage of tomatoes in polyethylene bag under ambient condition is a promising alternative to refrigeration to reduce wastage and consequently increase the marketable life of harvested tomatoes in tropical countries.Keywords: tomatoes, storage, low density polyethylene bags, ambient conditions

Quality characteristics and storage stability of emu meat nuggets formulated with finger millet (Eleusine coracana) flour

Purpose – The purpose of this study was to develop functional emu meat nuggets incorporated with finger millet flour (FMF) with high fibre content and improved oxidative stability. Design/methodology/approach – FMF was incorporated at 4, 6 and 8 per cent levels with replacement of emu meat in nuggets formulation and on the basis of various physico-chemical, instrumental colour and sensory parameters, 6 per cent FMF was selected as optimum. The functional emu meat nuggets incorporated with optimum level of FMF as well as control were aerobically packaged in low density polyethylene (LDPE) bags and stored for 21 days at refrigeration (4 ± 1°C) and evaluated for oxidative stability, microbiological quality and sensory attributes at regular interval of 7 days. Findings – The fat content showed significant (p &lt; 0.05) decrease, whereas the crude fibre content increased significantly (p &lt; 0.05) with the increasing levels of incorporation. The sensory scores for all the attributes in 6 per cent FMF-incorporated product were higher than control. During entire storage studies, the thiobarbituric acid reactive substances (TBARS), free fatty acid and peroxide value followed an increasing trend for control as well as treatment product; however, treatment showed a significantly (p &lt; 0.05) lower value than control throughout the storage period. Standard plate count increased significantly (p &lt; 0.05) for control and treatment product, but the counts were lower than the prescribed limits even on 21st day of storage. Practical implications – The developed products will have functional value by increasing the calcium and dietary fibre content by utilizing the minor cereals. This will be highly beneficial to both the agriculture and meat industry. Originality/value – The research findings demonstrated the use of FMF in the development of calcium- and fibre-enriched emu meat nuggets with improved oxidative stability.

Material Safety and Integrity of Water-Filled Low-Density Polyethylene Bags in an Accelerated Weathering Investigation for Applications in Solar Water Disinfection (SODIS)

In this work, the potential use of LDPE bags as containers in the SODIS application by simulated in an accelerated weathering tester (QUV), with respect to material safety and durability, was investigated. For the material integrity, a decrease in the elongation at break from 818% (at the beginning) to 21% (after 6 weeks of UV exposure) corresponded to the long UV exposure. A significant degree of mechanical degradation was evident during 2 to 4 weeks of UV exposure. The UV-Vis results showed that the UV transmittance of the bags, mostly in the UV-B region, decreased with longer duration of UV exposure. The FT-IR results showed a slight increase in carbonyl group, particularly observable in the bags exposed under UV for 3 weeks or longer. For the material safety, the amount of plastic additives that were leached into water was negligibily small and much lower than the limit of the safety standard. The results and analyses from this work provide insights into the feasibility of LDPE as an alternative material for SODIS containers and potentially be useful for future designs of SODIS containers to improve the disinfection and durability performances.

Meat Quality of Chicken Breast Subjected to Different Thawing Methods

Freezing is one of the methods to preserve and guarantee the quality of meat until it reaches the consumer. Even though freezing is classified as a mild form of preservation, it causes meat changes resulting from the formation of ice crystals that subsequently affect the tenderness and functionality of meat. The aim of this study was to evaluate the physicochemical and structural characteristics of chicken half breast submitted to fast freezing (-36 °C for 2 hours) and thawed by five different methods (under refrigeration, in a microwave, in a oven with air circulation, placed in cold water, or at room temperature). After thawing, the following parameters were evaluated: moisture content, drip loss (syneresis), water activity (aw), and shear force. Samples were also histologically evaluated by light microscopy. The results indicated that, despite being submitted to fast freezing, thawing affected (p <0.05) most of the physicochemical and structural properties of the meat, except for aw. Thawing in cold water (packed in low-density polyethylene bags and placed in cold water at approximately 10 °C for 2 hours and 15 minutes) presented the best results due to lesser damage to the cell structure, as shown by the lower drip loss, higher moisture content, and greater tenderness of the samples compared to those thawed using the other methods. Histological examination showed that muscle fiber structural features and organization were maintained. Thawing at low temperatures seems to cause less damage to the meat structure and allows maintaining of its properties. It was concluded that the meat quality is not related only with the freezing method, but also with the method and conditions used in thawing.

Stability of Capsaicinoids and Antioxidants in Dry Hot Peppers under Different Packaging and Storage Temperatures.

The maintenance of the quality and storage life of perishable fruits and vegetables is a major challenge for the food industry. In this study, the effects of different temperatures, packaging materials and storage time on the stability of capsaicinoids and antioxidants, such as total carotenoids, ascorbic acid and total phenolic compounds, were studied in three commercially cultivated hot pepper hybrids, namely Sky Red, Maha and Wonder King. For this purpose, dry whole pods were packed in jute bags and low-density polyethylene bags (LDPE), stored for five months under controlled conditions at 20, 25 or 30 ○C and analyzed on Day 0 and at 50-day intervals until Day 150. The three hot pepper hybrids differed significantly with respect to their capsaicinoids and antioxidant concentrations, but the results indicated that with the increase in storage temperature and time, a gradual and steady decrease in these levels was equally observed for all hybrids. Overall, mean concentrations after five months were significantly reduced by 22.6% for ascorbic acid, 19.0% for phenolic compounds, 17% for carotenoids and 12.7% for capsaicinoids. The trends of capsaicinoids and antioxidants evolution were decreasing gradually during storage until Day 150, this effect being more pronounced at higher temperature. Furthermore, the disappearance rates of capsaicinoids and antioxidants were higher in peppers packed in jute bags than in those wrapped with LDPE. In conclusion, despite the sensitivity of capsaicinoids and antioxidants to oxygen, light and moisture, the packaging in natural jute or synthetic LDPE plastic bags, as well as the storage at ambient temperature preserved between 77.4% and 87.3% of the initial amounts of these health- and nutrition-promoting compounds during five months’ storage.

Effects of NaOCl and LDPE Packaging on Postharvest Quality of Tomatoes

Postharvest storage study of tomatoes was carried out using low density polyethylene bag (LDPE) and chlorine cleaning (NaOCl) to compare the effects of NaOCl and LDPE. The postharvest quality of tomatoes was evaluated by monitoring and analyzing the parameters including weight loss, color change, titrable acidity (TA), total soluble solid (TSS), and firmness measurement in every two-day. It was found that tomatoes washed with clean water followed by packed in LDPE bag and stored at 15oC exhibited the best result by prolonging the self-life of 10 days. On the other hand, tomatoes washed in NaOCl followed by packed in LDPE and stored at 15oC was able to prolong the shelf life of 8 days. However, tomatoes were stored at ambient temperature under similar experimental condition; the shelf life was prolonged only 6 days. Furthermore, LDPE packaging storage was found good in retaining the firmness and lightness, however, NaOCl washing was led to soften and shrive the tomatoes rapidly.

Impact of collection container material and holding times on sample integrity for mercury and methylmercury in water

Mercury (Hg) and methylmercury (MeHg) concentrations in streamwater can vary on short timescales (hourly or less) during storm flow and on a diel cycle; the frequency and timing of sampling required to accurately characterize these dynamics may be difficult to accomplish manually. Automated sampling can assist in sample collection; however use has been limited for Hg and MeHg analysis due to stability concerns during extended storage times. We examined the viability of using automated samplers with disposable low‐density polyethylene (LDPE) sample bags to collect streamwater with high levels of Hg (&gt;45 ng L−1) and moderate levels of MeHg (0.2−2.5 ng L−1). Specifically, we investigated the effect of holding times ranging from hours to days on streamwater collected during baseflow and storm flow. Unfiltered and filtered Hg and MeHg concentrations decreased with increases in time before sample processing; holding times of 24 hours or less resulted in concentration changes (mean 11 ± 7% different) similar to variability in duplicates collected manually during analogous field conditions (mean 7 ± 10% different). Comparisons of samples collected with manual and automated techniques (holding times &lt; 24 h) throughout a year for a wide range of stream conditions were also found to be similar to differences observed between duplicate grab samples. These results demonstrate automated sampling into LDPE bags can be effectively used to collect streamwater for Hg and MeHg analysis, and encourage the testing of these materials and methods for implementation in other aqueous systems where high‐frequency sampling is warranted.

Effect of Modified Atmosphere Packaging on Storage of Baramasi lemon (Citrus limon(L.) Burm)

The harvesting period of winter crop of Baramasi lemon coincides with the cooler part of the year and there is often a glut like situation in the market at its peak harvest time. This results in low returns to the growers. A study was planned to enhance the storage life of baramasi lemon fruits and fruits were harvested at green mature stage along with small pedicel in the month of January. Only healthy fruits were dipped in 0.1% bavistin solution for 2 minutes and after shade drying fruits were packed (four fruits in each pack) in high density polyethylene (HDPE) and low density polyethylene (LDPE) bags. Fruits were also waxed with Citrashine wax in one treatment. Packed/treated fruits were packed in corrugated fibre board (CFB) boxes and kept at ambient conditions. Fruit samples were analysed after 20, 35 and 50 days of storage for various physico-chemical characteristics. Results revealed that fruits treated with bavistin @ 0.1% and packed in LDPE bags maintained the best fruit quality in terms of high sensory quality, juice content, acidity and low spoilage and physiological loss in weight during 50 days of ambient storage.