Assessment of agrochemical residues in banana fruit by using gas chromatography and QuEChers technique

Present study is performed to analyze the residues of agrochemicals in banana fruit sold in the Chandigarh region. Aim is to check whether the agrochemical waste of residues is within the maximum residue levels (MRLs) or not. Market survey was conducted in the fruit ripening godowns and it was observed that different toxic agrochemicals are being used in the banana cultivation and only 15% of working people were aware of chemicals and their harmful effects. The occurrence of some toxic agrochemical residues like endosulfan, carbendazim, chloropyripos, chlorthiophos was analyzed in the banana fruit samples taken from different markets areas of chandigarh. Multi-residue analysis was performed in peel and pulp differently for 10 different samples by gas chromatography mass spectrometer (GC MS). Chlorthiophos (organophosphorus pesticide) was found in three peel samples having range 0.004 – 0.23 mg kg−1 and one pulp sample have concentration 0.005 mg kg−1. Carbendazim concentration was in two peel samples have concentrations 0.002 and 0.07 mg kg−1. Endosulfan, chloropyrifus were absent in all samples whereas presence of carbendazim and chlorothiophos were found within MRL guidelines of Food and Agriculture Organization (FAO).

Assessment of Q(OP)D(PO) bleachability of softwood kraft pulp

Bleachability is evaluated as how easily a pulp sample is bleached and it depends on the structure of residual lignin and carbohydrates. Also, the bleachability varies depending on the bleaching sequence. ECF light sequences have been improved significantly in the recent years. However, we still don’t fully understand how ECF light bleach plants are optimally run. This work studies the bleachability of softwood kraft pulp in an ECF light bleaching sequence, (OO)Q(OP)D(PO). Three pulp samples with brown stock kappa number 27, 32 and 35 were bleached and studied for residual lignin, hexenuronic acid and carbohydrate content. It was found that in the bleaching stages that are highly delignifying, it is beneficial with a higher kappa number for the delignifying bleachability. However, in the bleaching stages where the objective is brightness increase, the brightness gain bleachability is improved by a lower kappa number. We also intended to determine which of the three samples had the best suited kappa number for this particular bleaching sequence. According to our results, the bleaching was most effective with kappa number around 32. Although an even higher kappa number resulted in higher yield after cooking, it seemed that this bleaching sequence cannot preserve the yield gain.

Evaluation of the Actual Chlorine Concentration and the Required Time for Pulp Dissolution Using Different Naocl Irrigating Solutions

INTRODUCTION The goal of root canal treatment is to shape and clean the endodontic space, reducing the bacterial load and removing the pulp tissue. Obviously, the action of the endodontic instruments is limited to the main canals, regardless of the complexity of the endodontic space. Consequently, finding the best possible cleaning technique, which can be obtained chemically using irrigation solutions, is a fundamental aid in the endodontic therapy. One of the most commonly used root canal irrigant is sodium hypochlorite (NaOCl), available in various commercial formulations. The effectiveness of NaOCl is undeniable. However, the action of dissolution of the pulp tissue is merely dependent on the concentration and the characteristics of the irrigant itself. AIM The aim of this study is to evaluate the effective concentration of different commercial formulas of sodium hypochlorite, by evaluating the percentage of total chlorine in each product. The dissolution capacity of the pulp tissue of each of the tested products was then analyzed by measuring the required time. MATERIALS AND METHODS Three commercial types of sodium hypochlorite were selected for this study: 5% NaOCl (ACE, Procter & Gamble), 5% NaOCl (N5, Simit Dental) and 6% NaOCl (CanalPro, Coltene). For each product, 10 packages were used, from which samples of the product were taken and 30 x 5 ml tubes were filled. All samples were divided into 3 groups and were analyzed using the DIN EN ISO 7393-2 method and the percentage of total chlorine (expressed as a percentage) was calculated. 40 samples of vital pulp were obtained from teeth freshly extracted for periodontal reasons and stored in physiological solution. In order to unify the size and weight of the samples (0.0001 mg), a microtome and a precision balance (Pro Explorer Ohaus) were used. Each sample, carefully examined by stereomicroscope (40x), was placed in artificial plastic containers and submerged in 0.1 ml of irrigating solution at room temperature (26 ° C). A fourth control group used saline solution as irrigant. Simultaneously with the insertion of the irrigating solution, a digital stopwatch was activated and the time necessary for the complete dissolution of the pulp sample was measured. The data obtained were subjected to statistical analysis. RESULTS The average percentages of chlorine detected for each group were: 4.26% (ACE), 5.16% (N5) and 5.97% (CanalPro). The Kruskal-Wallis test showed statistically significant differences between the different commercial formulations of hypochlorite (P <0.05). CanalPro showed the lowest values, while ACE showed the highest values of dissolution time of the pulp. DISCUSSION The analysis of the total chlorine percentage found that the actual concentration of the sodium hypochlorite in the samples is close to the values declared by the manufacturers both in the case of N5 and CanalPro. On the contrary, the concentration detected in the samples of common bench bleach (ACE) is significantly lower, which has average values less than 5%. This explains the longer time taken for the complete dissolution of the pulp tissue. The average dissolution time of the pulp samples was in fact inversely proportional to the concentration detected in the tested irrigants, so that a lower time corresponds to a higher concentration.

Effect of Ascophyllum nodosum seaweed extract on post-harvest 'Tommy Atkins’ mangoes

The aim of this study was to determine the effect of Ascophyllum nodosum extract (AN), applied in different doses on the physicochemical characteristics of post-harvest ‘Tommy Atkins’ mangoes. The selected mango fruits were treated with different extract concentrations (0%, 0.1%, 0.3%, 0.5% and 1.0%) and stored for 12 days at 25±2 °C and 75±5% RH. Every 3 days, fruit mass loss (PM), color angle (Hue) (AH), firmness, pH, titratable acidity (AT), content of total soluble solids in pulp (°Brix) and content of carbohydrates in shell were assessed. The experiments were carried out in CRD in a 5 x 5 factorial arrangement (concentrations x days of storage) with four replications. AN was effective in preventing PM, with a reduction of up to 40.2%, as observed at concentration 0.1% compared to control. There were no differences among concentrations on AH, however, all of them differed significantly from control with higher AH, especially on the 12nd day. Fruit firmness was lower in control, the pH increased with the storage time and AT decreased. For all these parameters, mangoes treated with the extract differed from control. The pulp sample °Brix increased with the storage time as well as the content of reducing sugars, with consequent reduction of non-reducing sugars in fruit shell. These tests indicate the possibility of using AN as an alternative management in preserving mangoes in the post-harvest stage.

Effect of storage temperature and duration on sugar content and sensory acceptability of strawberry pulp

Experiment was conducted to study the effect of different treatments on preservation of strawberry pulp at ambient and low storage temperature condition. The samples were pasteurized at 100°C for 15 minutes (T1), sodium benzoate 250 ppm (T2) and sodium benzoate 500 ppm (T3). The respective samples were stored for two months at room (25±5°C) and low (7±2°C) temperature conditions and reducing sugars; total sugar and sensory evaluation were recorded at three days of interval period. The results showed that the total sugar (%) increased in pulp sample maximum in T6 (5.9%) and minimum in T1 (4.8%), the maximum value regarding reducing sugars was recorded in T6 (4.9%) and minimum in T1 (1.4%) after 60th days of storage. However, reducing sugars and total sugar decreased in the stored pulp at room temperature and spoiled completely on 18th day of storage. The acceptability of organoleptic score decrease with the duration of storage in both ambient and low temperature. Among different treatments, sodium benzoate @ 500 ppm was found most effective and maintained the qualitative characteristics of preserved pulp at low (7±2°C) temperature condition. In future, these experimental results may prove very useful for storage of strawberry pulp for longer duration in better quality.

Processing of dissolving pulp in ionic liquids

This thesis forms part of the Council for Scientific and Industrial Research, Forestry and Forest Products Research Centre (CSIR-FFP) biorefinery project which aims at developing and implementing novel industrial processes production of cellulose textile fibres. The focus of this study is to investigate the dissolution of South African Eucalyptus raw (unbleached) and final (bleached) dissolving pulp and saw dust wood in an ionic liquid (IL) 1-ethyl-3-methylimidazolium acetate [Emim][OAc] and the co-solvents [dimethylsulfoxide (DMSO)] or [dimethylformamide (DMF)] mixtures, to obtain regenerated cellulose by the further addition of water and acetone. The IL/co-solvent mixtures were able to dissolve the raw and final pulp samples at 120 ˚C for 6 hours whereas the sawdust wood dissolved in 10 hours. The IL/DMF mixture gave higher cellulose recoveries of 41.88 % for the raw pulp, 49.89 % for the final pulp sample and 32.50 % for sawdust wood while the IL/DMSO mixture gave a recovery of 15.25 % for the raw pulp sample, 36.25 % for the final pulp sample and 17.83 % for the sawdust wood sample. The regenerated cellulose materials were characterized by Fourier Transformer Infrared Spectroscopy (FTIR), Nuclear Magnetic Resonance (NMR), Scanning Electron Microscopy (SEM), Thermo gravimetric Analysis (TGA) and Powder X-Ray Diffraction (pXRD), and compared with a standard microcrystalline of cellulose. It was observed that the FTIR and NMR spectra of the regenerated cellulose and MCC were similar which then indicates that no chemical reaction occurred during the dissolution and regeneration process of cellulose. SEM and X-ray diffraction (XRD) patterns of the results showed that after dissolution the cellulose I (native form), the crystalline structure was completely converted into cellulose II (amorphous) structure, and this was due to the removal of lignin and decrease in cellulose crystallinity. TGA results showed that the regenerated cellulose samples have higher char yields compared to the MCC which is due to the IL remaining in the regenerated cellulose. It was also observed that the addition of the co-solvents decreased the viscosity of the IL mixture, facilitating dissolution of the cellulose that led to additional swelling and reduction of the recalcitrant nature of the cellulose crystalline structure and intermolecular interactions. This led to increased accessibility and dissolution of the cellulose. The findings in this study have the potential to bring ILs closer to applications for biomass technology in particular for an economically viable dissolution method for biomass because ILs have a benefit of being easily separated from the anti-solvent, which provides a simple solution for IL recycle ability and re-use. The novel aspect of this study is: . This is the first study in the South African context to examine the influence of the lignin on the dissolution and regeneration of Eucalyptus sawdust wood and dissolving pulp.

Quantifying microstickies via a new agglomeration technique

Despite the recognized importance of microstickies to the various deposition problems experienced in pulping, papermaking, and printing operations, there is still no consensus on a proper method to quantify them. One proposed method is to agglomerate microstickies in a pulp sample by long cold storage or by exposure to reduced pressure conditions followed by a classification step to isolate them from the pulp as macrostickies. In this paper, we tested this approach, but using a more effective agglomeration method to convert microstickies into macrostickies. We found that microstickies in mill samples could be agglomerated into macrostickies by boiling whole pulp suspension. The best agglomeration conditions occurred on 1% consistency pulp stirred at 250 rpm during heating, at a heating time of 45 min, with subsequent maintenance of boiling for 60 min followed by a cooling period of 3 h at room temperature. Polyacrylate type microstickies appeared to respond best to the boiling agglomeration method. To see how effective the boiling method was in agglomerating microstickies into macrostickies, a model pulp with a known quantity of model stickies was made. Using this model stickies suspension, the boiling method was proven to be very efficient for agglomerating microstickies into macrostickies by converting up to 70% of the microstickies into macrostickies. Photomicrographs clearly demonstrated that the macrostickies collected after boiling treatment were mainly formed by microstickies agglomeration.

Diet selection is related to breeding status in two frugivorous hornbill species of Central Africa

Avian diet selection is hypothesized to be sensitive to seasonal changes in breeding status, but few tests exist for frugivorous tropical birds. Frugivorous birds provide an interesting test case because fruits are relatively deficient in minerals critical for reproduction. Here, we quantify annual patterns of fruit availability and diet for two frugivorous hornbill (Bucerotidae) species over a 5.5-y period to test for patterns of diet selection. Data from the lowland tropical rain forest of the Dja Reserve, Cameroon, are used to generate two nutritional indices. One index estimates the nutrient concentration of the diet chosen by Ceratogymna atrata and Bycanistes albotibialis on a monthly basis using 3165 feeding observations combined with fruit pulp sample data. The second index is an estimate of nutrient concentration of a non-selective or neutral diet across the study area based on tree fruiting phenology, vegetation survey and fruit-pulp sample data. Fifty-nine fruit pulp samples representing 40 species were analysed for 16 nutrient categories to contribute to both indices. Pulp samples accounted for approximately 75% of the observed diets. The results support expected patterns of nutrient selection. The two hornbill species selected a diet rich in calcium during the early breeding season (significantly so for B. albotibialis in July and August). Through the brooding and fledging periods, they switched from a calcium-rich diet to one rich in iron and caloric content as well as supplemental protein in the form of invertebrates. Calcium, the calcium to phosphorus ratio and fat concentration were the strongest predictors of breeding success (significant for calcium and Ca:P for B. albotibialis in June). We conclude that hornbills actively select fruit based on nutritional concentration and mineral concentration and that the indices developed here are useful for assessing frugivore diet over time.

Improvement in the Fock test for determining the reactivity of dissolving pulp

The Fock test is widely used for assessing the reactivity of dissolving pulp. The objective of this study was to modify the method to improve the repeatability of the test. Various parameters that affect the repeatability of the Fock test were investigated. The results showed that Fock reactivity is dependent on testing conditions affecting the xanthation between cellulose and carbon disulfide, such as the moisture content of the pulp sample, sodium hydroxide (NaOH) concentration, xanthation temperature, carbon disulfide dosage, and xanthation time. The repeatability of the test was significantly improved using the following modified testing procedure: air dried sample in the constant temperature/humidity room, xanthation temperature of 66°F (19°C) in a water bath, xanthation time of 3 h, NaOH concentration of 9% (w/w), and 1.3 mL carbon disulfide.

Action Mechanism of the Improvement of Printability for Eucalypt Bleached Kraft Pulp Pretreated by Cellulase

Enzymatic refining of eucalypt bleached kraft pulp with the cellulase NOV476 was studied. The effects of this cellulase on the physical properties of pulp, fiber morphology and fiber appearance of the eucalypt bleached kraft pulp in different application conditions were discussed. The results show that, with the increase in the amount of enzyme, tensile strength index, burst index and TEA index of paper are increased and then decreased; elongation and tear index of paper have been declining, Zeeil tensile strength index has been an upward trend. Without beating the pulp sample, gradually increases as the amount of enzyme, the average fiber length and the average fiber width are gradually reduced, while mean kink index substantially constant. Number of vessels in fiber overall reduced tendency reaches a minimum in the amount of enzyme 0.5μ/g, the phenomenon is most obvious. In the same conditions of beating time, gradually increases as the amount of enzyme, the average fiber length is gradually reduced, an average fiber width is gradually increased, the mean kink index reaches a maximum in the amount of enzyme is 0.5μ/g. Number of vessels in fiber overall reduced trend.