Storage Of Pulp Research Articles

Pulpa de pimentón (Capsicum annuum L.) congelada, estabilizada para sopa: evaluación nutricional y sensorial

The aim of this investigation was to elaborate soups from frozen pulp of organic pepper (Capsicum annum L. cv. Fyuco). Peppers were organically cultivated at the plots of Universidad Catolica del Maule, San Isidro Campus Los Niches Sector, Curico, Region VII, Chile. This research had three treatments: T0 corresponding to control treatment, T1: pepper pulp, plus stabilizer (Carrageenan Caraol PFP 5337), T2: pepper pulp, plus stabilizer and sweetener (stevia). Chemical assessments (Soluble solids (°Brix), ascorbic acid (mg.100 g-1), acidity (%) and reducing sugars (%)) and sensorial (Flavour, texture, colour, smell, appearance and acceptability) were carried out at days 0, 30 and 60. A microbiological analysis was performed by counting the total coliforms to guarantee the safety of the different treatments. The data obtained in the analyses were assessed with a completely random block design (DBCA), for the chemical and sensorial analyses, all of them having a confidence level of 95 %. There were no significant differences in the chemical parameters under study during the period of the pulp storage, sensorial analysis performed during the three times did not show significant differences. Key Words: frozen soup, peppers, sensorial attributes.

ASSESSMENT OF THE EFFICIENCY OF ENVIRONMENTAL COMPONENTS IN THE OCCUPATIONAL SAFETY MANAGEMENT SYSTEM AT SUGAR FACTORIES OF UKRAINE

The article considers the importance of sugar mills' environment, conditions, and occupational safety. According to modern requirements, the efficiency of an enterprise should be determined not only using the cost of outproducts but by a comprehensive strategic assessment of energy efficiency, technological safety, impact on the environment, and working conditions at workplaces. The critical driving force for the development of modern technologies is effective approaches to determine the economical components of the environmental impact assessments, as well as management systems to improve conditions and occupational safety at workplaces of sugar production. At the same time, it is necessary to optimize the use of electricity, natural gas, coal, and freshwater with the maximum quality of products at the sugar factories of Ukraine. To economically substantiate the safety and environmental components based on legal, economic, and social requirements in sugar production, these components were analyzed regarding occupational safety, identification of problems, drawbacks in the management, and the regulatory and legal systems of occupational safety. The main environmental factors of sugar production are greenhouse gases emission. These emissions result from using natural gas; the electricity produced by the energy system of Ukraine; decarbonization of limestone; and pulp storage. All these components affect the working conditions at workplaces and the environment. Considering these components and their impact on working conditions and the environment with certain features of the technological process of sugar production, the general economic and social approaches to determine the effectiveness of occupational safety and environmental safety in the system "human-machine-environment" were worked out. It was established that improving working conditions and safety and normalizing ecological impacts can reduce the consumption of natural gas (up to 17%); electricity (about 6.7%) and significantly reduce the amount of carbon dioxide and methane as the leading greenhouse gases. Furthermore, the rationalization of workplace organization in the sugar production management system can increase labor productivity by up to 20%. The introduction of the assessments that consider the safety, legal and environmental components of the system "human-machine-environment" makes it possible to increase the efficiency of sugar production management. Keywords: economic efficiency, social efficiency, environmental safety, sugar production, occupational safety, working conditions, assessment.

Using novel DNA methods to achieve higher process efficiency and performance

Uncontrolled microbiological activity is a challenge for recycled fiber (RCF) mills as it can have negative effects on production and end-product quality. The microbes that exist in these systems have been largely unknown, and the strategies employed to control microbiology have been non-specific. Understanding the specific microbial groups present in RCF mills, their properties, and where they exist, as well as having the ability to accurately measure the true troublemakers, are key to targeted control of the bad actors. In this study, we present the results of a global survey of over 40 RCF paper machines. The same RCF-specific problem-causing bacterial groups were found on different continents, including large densities of newly identified bacteria in paper processes. Those can degrade cellulose and starch, produce acids and odorous substances, and have a significant impact on fiber strength and additive consumption. We also demonstrate how modern DNA tools can quantify the impact of biocidal countermeasures against the actual troublemakers, including bacteria found to degrade cellulose during RCF pulp storage, which may be linked to a negative impact on end-product strength. These novel DNA tools give producers updated biocide program key performance indicators (KPIs) and actionable information to more effectively design and adjust microbiological control to achieve higher process efficiency and performance.

Research on the Rose Wines Production in Azerbaijan

The native Matrasa grapes variety grown in the Samukh (79 m), Ganja (408 m) and Goygol (630 m) districts located at different altitudes above sea level, was used. Storage of pulp was carried out at different times — 3, 6, 12, 24 hours. Before maceration, desulfurization of the pulp is carried out. As a result of the tasting conducted according to a 10-point system with the participation of 9 tasters, a sample of rose wine aged in a pulp for 6 hours became more noticeable due to its transparency and color. At the same time, in terms of taste, typicality, aroma and bouquet, this sample was more preferable and eventually received a score of 9.6 points. Although there was no sharp difference between the number of aromatic substances in wine materials obtained from the Matrasa grape variety grown in different regions, some differences were still noticeable. Thus, the total amount of aromatic substances was 90.9 mg/dm3 in the wine material from the Goygol district, 88.6 mg/dm3 in Ganja and 85.6 mg/dm3 in Samukh. It turned out that in the sample of Samukh wine the content of acetates of higher alcohols was 5.7 mg/dm3, in Goygol — 5.2 mg/dm3 and, finally, in Ganja — 4.6 mg/dm3. Looking at the number of esters in both tables, it becomes clear that in the samples of wine from fatty acid esters the most common ethylhexanoate (1040-1210 mg/dm3) and ethyl-4-ONE-butanoate (1015-1430 mg/dm3).

Pectinmethylesterase affects the flow behavior of orange pulp.

In the orange juice industry, pulp (ruptured juice sacs) is separated from the juice after extraction and pasteurized separately before blending back with juice or sold for other food applications. However, pulp is not always pasteurized immediately after extraction and the flow behavior is affected by endogenous pectinmethylesterase (PME). This is particularly important because of the high power required to pump orange pulp in industrial pasteurizers. This study characterized the effect of PME on the flow behavior of citrus pulp during storage at 4 °C using rotational rheometry and during pulp storage at 22 °C using capillary rheometry. PME activity was 0.011± 0.001 PEU for the pulp used in rotational rheometry and 0.030± 0.002 PEU for the pulp used in capillary rheometry. Rotational rheometry was used to assess the effect of PME on the Power Law parameters at shear rates ( ) below those that cause slip. There were no significant differences among storage time on the flow behavior index (n). However, the consistency coefficient (K) increased with storage time. Significant differences were found after 12-hr storage increasing from 120± 30Pa·sn to 160± 15Pa·sn (16.7%) after 24 hr. Capillary rheomtery was used to assess the effect of PME on the pressure drop in a flow system. Significant differences were found at or after 12-hr storage. The mean pressure drop increased by 34% after 24 hr, for a flow rate of 50×10-6 m3 /s (0.8 GPM) in an 8.9-m long (29.2ft), 0.022-m (1-in) diameter pipe. PRACTICAL APPLICATION: Design and optimization of processing equipment and industrial handling systems of orange pulp require detailed knowledge of its rheological (flow) properties. Citrus pulp is rich in pectinmethylesterase, an enzyme that causes thickening of the product when not inactivated during pasteurization. Understanding how fast PME affects the flow properties of orange pulp is important for citrus processors to decide how long pulp can be stored before pasteurizing it.

Effects of Freeze-drying and Freezing on Vitamins and Sugars of Mango Pulp (‘Apple’ Cultivar): A Preliminary Comparison of Methods for Improving Sample Storage

Mango (Mangifera indica L.) fruits are highly perishable ones whose important nutrients such as vitamins and sugars quickly decrease under storage. In this study, we compared two methods of fruit pulp storage; freezing and freeze-drying in order to compare total carotenoids, β-carotene, ascorbic acid (AA), titratable acidity (TTA), total soluble solid (TSS) and pH. Mean total carotenoid, β-carotene and AA of frozen pulp were 7.08±0.15 µg/g, 1.47±0.09 µg/g and 92.77±17.49 mg/100 g respectively. While freeze-dried pulp had 8.06±0.03 µg/g, 2.35±0.03 µg/g and 113.02±0.07 mg/100 g for total carotenoid, β-carotene and AA respectively. The total carotenoid, β-carotene and AA of fresh pulp were; 8.15 µg/g, 2.44 µg/g and 119 mg/100 g respectively. TTA, TSS and pH were; 3.01±1.01%, 9.40±1.42 °Brix and 2.97±0.19 for frozen pulp and 2.97±0.01%, 11.70±0.08 °Brix and 2.99±0.01 for freeze dried pulp respectively. TTA, TSS and pH for fresh pulp were; 4.85%, 11.90 Brix% and 3.48 respectively. All measured parameters were significantly higher (p <0.05) in fresh sample than in the stored pulp (frozen or freeze-dried). Mean total carotenoids, β carotene, AA and TSS were significantly (p <0.05) higher for freeze-dried pulp than for frozen pulp. However, mean TTA and pH did not differ between freeze-dried and frozen pulp. Slow decrease of AA in the freeze-dried pulp further suggests the method as preferred for long term storage of mango pulps.

Identification and control of the lateritic mineral pulp storage process

Identification and control of the lateritic mineral pulp storage process

Effect of some preservation techniques on quality parameters and antioxidant properties of banana pulp during storage

Banana is a highly nutritious fruit that can be used for production of various novel foods. Although economical, its limited shelf life hinders the storage of pulp for processing purposes. Chemical (0.1 and 0.1% KMS), thermal (65 °C for 30 min) and a combination of both thermal & chemical treatment was applied to freshly prepared banana pulp and various quality parameters of treated as well as untreated (control) pulp were studied for a storage period of 90 days. All the studied parameters viz; acidity, pH, TSS, reducing and non-reducing sugars varied significantly with different treatments during storage. Color, PPO activity and antioxidant properties (DPPH, ABTS and total phenolic content) were also determined. Chemically treated pulp showed highest values of total phenolic content (0.96–0.44 mg GAE/g dfw) but lowest DPPH (IC50 = 4.42–32.42 mg/ml) and ABTS (IC50 = 3.15–21.37 mg/ml) values. Although lowest values of PPO activity (158.65 units) was seen in samples that were subjected to dual (chemical and thermal) treatment, however lowest change in color index (1.09–58.49) among all the samples during storage was seen in chemically treated samples. Dual treatment was more showed lesser total plate count than samples that were heat or chemically treated samples. All treatments resulted in improved sensory attributes during storage and prolonged the shelf life of samples in comparison to control. Chemical treatment was most effective in preserving quality parameters viz; color and antioxidant activity but samples treated with a combination of thermal and chemical treatment could be stored for longer period without deterioration than rest of the samples.

Reactions between peracetic acid and lipophilic extractives – methodologies and implications in post bleaching of kraft pulps

Abstract Pulp mills constantly look for opportunities to increase their production capacity without major investments, as well as to save in overall bleaching costs. Peracetic acid (PAA) is used in post bleaching of kraft pulps to increase pulp brightness, to prevent brightness reversion in pulp storage, and to prohibit problems caused by extractives. However, the rates and significance of reactions between PAA and lipophilic extractives in pulp bleaching are not known in detail. Hence, the reactions between PAA and model compounds of extractives have been studied as emulsions in water and directly in methyl-tert-butyl ether (MTBE). Unsaturated compounds were found to be reactive in both water and MTBE, and the conventional extractive analyses had to be modified. Freeze-drying the reaction mixture with subsequent trimethylsilylation and GC-analysis was a very effective analytical approach. As a result of PAA treatment, fatty acids and sterols with double bonds were shown to form epoxides and the corresponding diols. Dehydroabietic acid (DeAb) also reacted with PAA by oxidation of the benzylic position. After longer reaction times, the reaction products of the extractives were further degraded or formed cross-linked aggregates. The epoxides and diols were also identified in samples from pulp mills applying PAA in post bleaching.

The influence of process waters on optical properties during storage of hydrogen-peroxide bleached Norway spruce mechanical pulp

Abstract To evaluate the causes behind the formation of colour in mill systems, the effect of different process waters on the optical properties of hydrogenperoxide bleached Norway spruce mechanical pulp during storage was studied. The influence of process water type, temperature, time, pulp consistency and pH was evaluated over the visible range of wavelengths. The darkening was more pronounced when pulp was stored in process waters compared to in distilled water. Increased temperature and prolonged storage times increased the darkening as expected, whereas a higher storage consistency gave less darkening than a lower storage consistency (15% compared to 5%). The pH value that gave the lowest brightness reduction and a minimum in Δk460 was found to be 5.5-6.0. Storage of pulp in white water from the paper machine resulted in a broad shoulder in the k spectra indicating colour formation related to the particles in this water. Part of this shoulder in absorption spectra was related to added dyes, but the increase in absorption with time is likely to be caused by some other colour formation. The colour measured as a*, b* showed that the storage changed the colour of the pulp towards red and yellow, and initially more towards red.

Cracking analysis of 316L stainless steel lining plates in alkaline environments

Grade 316L stainless steel has good corrosion resistance properties in alkaline environments. In this project, 2mm thick 316L lining plates were welded onto the A36 steel wall of a pulp storage tower to aid in corrosion resistance. After more than 1year of service, the 316L lining plates were found cracked. The current study performed physical and chemical inspection using a Stereo Microscope (SM), Scanning Electron Microscopy (SEM) and an Energy Dispersive Spectrometer (EDS) to understand the root cause of the cracking of 316L shell plates. It was concluded that crevice corrosion, which triggered Stress Corrosion Cracking (SCC), took place between 316L and A36 as a result of exposure to pulp. The presence of δ-ferrite on the welds and a Heat-affected Zone (HAZ) decreased the corrosion resistance properties. The combination of welding stress and a corrosive environment led to SCC of the 316L plates.

MECHANICAL PULPING: The influence of process conditions during pulp storage on the optical properties of Norway spruce mechanical pulps

The objective of this thesis is to determine possible causes of the darkening of hydrogen peroxide bleached mechanical pulp over the visible spectrum and their relative contributions. It focuses on both process conditions and the composition of the pulp and the dilution water, including additions or losses of material along the process line from the bleach tower to the paper machine.A mapping of the optical properties of the pulp along the process showed that the fine fraction of the pulp darkened more than the long fibre fraction. Simulation of retention times of different fractions showed that the main part of the fine material is retained in the paper within a few hours, a small part might circulate for considerably longer time and may therefore be strongly coloured.Storage trials were mainly performed using a hydrogen peroxide bleached mechanical pulp intended for SC paper made of Norway spruce (Picea abies), sampled on one occasion and stored in a freezer. Unwashed or well-washed pulp was stored in distilled water or in different process waters. Some complementary trials were included, e.g. unbleached pulp.Time and temperature were the process variables that gave the strongest darkening of the pulp, as expected, both in a clean and a more process-like system, whereas pH only had an effect in the presence of process waters; the highest brightness stability was seen at a pH around 5.5–6.0.The darkening was due to an increase in the light absorption coefficient (k) beginning at short wavelengths, but after longer storage times the increase in kλ also became noticeable at longer wavelengths. The colour (CIE L*, a*, b*) of the pulp changed towards red and yellow, initially more towards red and then more towards yellow. These changes were clearly visible.Washing of the bleached pulp made it less sensitive to storage; possibly due to the removal of extractives, lignin-like substances, metals and pulp fines. This washing had little effect before storage and the amount of material removed was small.The pulp darkened more when stored in process waters compared to distilled water. Apart from fibres, most of the colour was associated with pulp fines or filler but some colour was also found in the dissolved and colloidal fractions. At an increased pulp consistency, the increase in k460 was smaller.Storage in white water from the paper machine gave extensive discolouration with a shoulder in the absorption spectrum around 550–650 nm, which increased with time. The addition of ferric ions increased the light absorption coefficient during storage, but could not explain the increased absorption at 550–650 nm nor could it be the only cause of the darkening in the mill system. A cationic basic violet dye gave a shoulder in the absorption spectrum similar to that of the mill system, but the absorption of the dye did not increase during storage. Model calculations indicate, but do not prove, that ferric ions together with violet and red dyes could have played a major, but not exclusive role in the colour observed in the mill system after storage. The darkening not accounted for, at longer wavelengths and around 550–650 nm, is suggested to be related to fines and fillers including dissolved and colloidal substances associated with these particles.A method to produce representative sheets for determination of optical properties of mechanical pulps was developed. The new method makes it possible to follow changes in light absorption and light scattering coefficients over the visible range of wavelengths. It is approximately six times faster than standard methods, reduces the risk of additional darkening of the sample and can be used with small pulp quantities.The deviation from the expected linear behaviour of the light scattering coefficient, s, at wavelengths corresponding to strong light absorption has been studied using the Kubelka-Munk model and the angular resolved DORT2002 radiative transfer solution method. The decrease in s could not be explained by errors introduced in the Kubelka-Munk modelling by anisotropic scattering.

Modifikation der Zellwand und Oberfläche von ungebleichten lignozellulosischen Fasern infolge einer Temperaturbehandlung – Einflüsse auf die Zugfestigkeit von ungemahlenem Kraftzellstoff

The effects of heating lab cooked never dried kraft pulp from pine and spruce at 5 % consistency to 80, 100 and 120 °C in a pressurized vessel were evaluated based on various fiber and sheet properties. The settings of pH and conductivity in the lab trial were chosen in accordance with operations such as oxygen delignification, alkaline extraction, washing or storage of pulp in an integrated paper mill. It was found that the tensile strength was reduced steadily with increasing temperature. Nuclear magnetic resonance spectroscopy showed that fiber crystallinity and pore size increased at high temperatures compared to the unheated reference. Crystallinity most likely affected the fiber flexibility and thus resulted in less and weaker fiber–fiber bonds. Atomic force microscopy indicated that the amount of precipitated lignin granules on the fiber surface was reduced with increasing temperature. The roughness of the fiber surface did not significantly change with temperature and hence did not negatively influence the tensile strength. It was remarkable that a so called reversed latency was observed. Instead of a decrease in fiber curl with temperature, the fiber became significantly more curled. A large portion of the losses in tensile strength was attributed to the increase in fiber curl and leaching of hemicelluloses from the fiber wall.

Integrating sugar beet pulp storage, hydrolysis and fermentation for fuel ethanol production

Sugar beet pulp (SBP) as received has a fairly high moisture content of 75–85%, which makes SBP storage a challenge. Ensilage was studied over 90days and was found to effectively preserve SBP without lactic acid bacterium inoculation. Higher packing density yielded a slightly better silage quality. Ensilage improved sugar yield upon enzymatic hydrolysis of ensiled SBP washed with water. However, neither washing nor sterilization improved ethanol production from ensiled SBP using Escherichia coli KO11, suggesting ensiled SBP could be used directly in fermentation. The ethanol yield from ensiled SBP was nearly 50% higher than raw SBP. Fed-batch fermentation obtained approximately 30% higher ethanol yield than batch. Fed-batch could also be carried out at 12% solid loading with a 50% lower enzyme dosage compared to batch at the same solid loading, indicating opportunities to improve the economics of SBP conversion into liquid fuels.

Evaluation of the Technological Potential of Gabiroba [Campomanesia xanthocarpa Berg] Fruit

Native fruits are receiving special attention from food researchers all around the world. The Campomanesia xanthocarpa Berg [gabirobeira] is a species native to Brazil, being part of family Myrtaceae. The gabirobeira produces a fruit named gabiroba, whose pulp presents a nice acidic-sweet taste. This work was aimed at evaluating the gabiroba technological potential for use as a raw material for the food industry. The gabiroba pulp was evaluated for its physical-chemical features. In addition, the pectin that was extracted from the pulp was evaluated for its rheological features. The pulp bioactive compounds content, namely vitamin C, flavonoids, phenolics and carotenoids, was measured during 180 days of freezer storage. The pulp antioxidant capacity was measured by means of the DPPH and ABTS methods. The rheological measurements were performed through the use of a Haake RS 75 rheometer. The generated flow curves were fitted by means of the Power Law and Herschel-Bulkley models. Results show that the gabiroba contains remarkable contents of iron, phosphorus, zinc, manganese, total phenolics [131.90 mg/100 g, expressed as galic acid], vitamin C [312.21 mg/100 g] and total carotenoids [290.84 μg/g]. About 42% of the carotenoids corresponded to beta-carotene. During pulp storage, it was observed a decrease of 10.00% in total phenolics content, 5.35% in flavonoids and 23.52% in the vitamin C. There was a positive and significant correlation between antioxidant capacity and bioactive compounds content, suggesting that such capacity might be influenced in a synergic way by the detected bioactive compounds. The gabiroba pulp pectin presented a shearthinning behavior, being the data best fitted by the Herschel-Bulkley model. The viscoelastic measurements showed that the dynamic moduli are frequency independent. Concluding, gabiroba showed a remarkable potential to be used as a raw material in the food industry due to its rheological, functional [phytochemicals], sensory and nutritional [vitamins and mineral salts] features. Despite their large fructification, in addition to nutritional and attractive sensory characteristics, these fruits are not collected, being lost in the fields. In this work, the fruit pulp without seed [1500 g] was crushed in ethanol/water at a ratio of 1:4 [v/v], refluxed for 15 minutes at boiling temperature. The residue obtained was subjected to sequential extractions. The extractions were optimized using a factorial design 22, with the concentration of citric acid [0.5 and 5%] and temperature [50 and 100oC] as variables. The polysaccharides were characterized according to their chemical composition and rheological profile. The high concentrations of uronic acids, arabinose and galactose, detected in all fractions, indicate that they consist of pectin. The results showed that the extraction method was efficient for fractionation of pectin from different areas of the cell wall. The polysaccharides extracted from the fruit pulp of gabiroba showed a pseudoplastic behavior. All the fractions were resistant to temperature variations. When these gels are heated up and cooled down, they adopt their original structure.

Survival and dispersal of Puccinia psidii spores in eucalypt wood products

The rust, caused by Puccinia psidii, is one of the most important diseases of Eucalyptus and other Myrtaceae. The disease can be spread by windblown fungal spores, infected rootted cuttings, seedlings, pollen and other host tissues that increase the risk of its introduction to rust free countries as well as of spreading new pathogen lineages. To assess the risk of disease spread by transport of spores on wood products, we evaluated the effect of height of traps installed in different eucalypt timber and wood pulp storage areas on rust spore capture. We also evaluated P. psidii spore dispersal in the field and survival of P. psidii urediniospores and teliospores under different temperatures (15, 25, 30, and 35°C) and relative humidity (35, 55, 70 and 87%) for up to 120 days. Spore viability was evaluated in vivo by germination on leaves of a susceptible hybrid E. urophylla x E. grandis clone and by staining with fluorescein diacetate. The number of P. psidii spores captured in timber and wood pulp storage areas was significantly lower than in eucalypt plantations that contained infected plants. A combination of high temperature and high relative humidity decreased spore survival. Urediniospores and teliospores survived 90 days at 15°C and 35% relative humidity, but only 10 days at 25 to 30°C and 70% relative humidity. The results of this study indicated that although rust spores may reach wood products (timber and pulp) storage areas in very low numbers, the adverse environmental conditions encountered in these areas and during overseas transport do not favor spore survival. Thus, the risk of spread of this pathogen into new areas in the absence of infected host plants is considered extremely low to inexistent.

THE EFFECT OF PASTEURIZATION ON THE QUALITY OF FROZEN ARAZÁ (EUGENIA STIPITATA MC VAUGH) PULP

ABSTRACT The effects of pasteurization on the quality of frozen arazá pulp were investigated. Arazá pulp was pasteurized at 65, 73, and 80C before being placed in frozen storage at −20C for a period of 60 days. After pasteurization (day 0 of frozen storage), no changes in color, aroma, or texture were observed; nevertheless, taste, vitamin C, and antioxidant activity (AA) were negatively affected. After 60 days of frozen storage, a decrease in the AA and a decrease in both vitamin C and phenolic levels were observed, with the exception of the unpasteurized pulp, for which there were no differences in the AA‐ferric reducing antioxidant power and phenolics before and after the 60 days of frozen storage. No correlation was found between phenolics and AA, which could be due to differential changes in the phenolics composition that were not measured in this work. The decimal reduction time in days of vitamin C was 92, 89, 112, and 176 for the control and the pasteurized pulps (at 65, 73, and 80C), respectively. Pasteurization at 80C before freezing at −20C could be a successful technique to extend the shelf life of arazá pulp. PRACTICAL APPLICATIONSThis research was developed to study the effect of pasteurization on the quality of arazá pulp during frozen storage. The pasteurization of pulp at 80C with a holding time of 1 min before frozen storage at −20C controls vitamin C and the sensory characteristics of degradation. These traditional techniques can help food industries dealing with arazá pulp storage obtain a more stable product for at least two months.

Studies on Microbial and Sensory Quality of Mango Pulp Storage with Chemical Preservatives

The effect of chemical preservatives of sodium benzoate, potassium metabisulphite and potassium sorbet used individually and in combination, was studied on the microbial and sensory quality of the mango pulp (packed in 1kg glass and plastic containers) stored at ambient temperature (30-36 C) for o 90 days with an interval of fifteen days. Mean score of taste panel for color, flavor and overall acceptability significantly (p<0.01) decreased, while microbial growth significantly (p<0.01) increased during storage. Results showed that samples with 0.2% potassium metabisulphite packed in plastic containers had negligible microbial growth, maintained maximum nutrients stability and best quality characteristics during storage.

Factors Influencing the Stability of Frozen Kiwifruit Pulp

ABSTRACTThe biochemical, sensory, and quality changes that occur during processing and prolonged frozen storage of kiwifruit pulp were studied. The temperature and processing time during pulp manufacture and freezing are critical factors in determining the % total chlorophyll and color of the frozen pulp. Storage of pulp at acceptable commercial frozen storage temperatures (−18°C or below) for 12 months resulted in a stable color, and a slight decrease in the % total chlorophylls and ascorbic acid. The type of packaging material used and deaeration of pulp did not influence the above findings. The sensory qualities of the pulp were not affected by the storage conditions.

Effects of pulp freezing and frozen pulp storage on fibre characteristics

A requirement of long-term research on pulp fibres in that the material for study be stored for prolonged periods without deterioration and without changes in properties. In this paper effects of pulp freezing and thawing and of frozen pulp storage on fibre, wet web, and handsheet properties are discussed. A variety of radiata pine kraft pulps, a radiata pine sodium bisulphite pulp, and silver beech and hard beech (Nothofagus species) kraft pulps are examined.