Lignin oxidation by PCD technology

The purpose of this study is to investigate whether commercial Kraft lignin can be treated with pulsed corona discharge apparatus so that it becomes active. Active lignin refers to the kind of lignin that can be precipitated on the surface of a fiber by lowering the pH. A secondary agenda here is to remove the pungent smell of kraft lignin, which is caused by organically bound sulfur. It is expected that the study will identify mild processing conditions and parameters for achievement of the desired outcome. In the literature review, the properties of lignin are explained, as is their impact on any further processing. In addition, a number of processes are described for the oxidation of lignin in a variety of applications. In the experimental part of the study, test runs were conducted to determine the effects of oxygen supply and pulse frequency on oxidation results, where the purpose is to produce reactive lignin and to find a process that is feasible at an industrial scale. Based on the reported experiments, lignin could not be made active or precipitated to the surface of the fiber. Actual changes in the structure of lignin were not observed, but the pungent smell of lignin was removed. The exact reason for this change could not be established because sulfur NMR analysis did not work for the lignin samples.

Development of an alternative technology for the oyster mushroom production using liquid inoculum

Pleurotus ostreatus, worldwide known as oyster mushroom, was cultivated in banana straw using inocula produced by two different processes - liquid inoculum and the traditionally used solid inoculum. Different ratios (5, 10, 15, and 20%) were tested. Biological efficiency, yield, productivity, organic matter loss, and moisture of fruiting bodies as well as physical-chemical characteristics of banana straw were studied. Significant differences were observed for cellulose, lignin, and hemicellulose content between one and two harvests for both solid and liquid inocula. It was observed that P. ostreatus growth promoted higher degradation of lignin (80.36%), followed by hemicellulose (78.64%) and cellulose (60.37%). Significant differences between one and two harvests were also observed for the production parameters (biological efficiency and yield) for both kinds of inocula, liquid and solid. However, significant differences in productivity between harvests were observed only for solid inoculum.

Study of clarification process of sugar cane juice for consumption

Sugar cane juice or garapa darkens quickly after extraction due to the oxidation of some of its constituents harming its commercialization thus requiring rapid consumption. The objective of this study was to develop a mild process for sugar cane clarification, obtaining a cloudy, greenish-yellow beverage. The following parameters were combined to aiming at this objective: heat treatment at 65 ºC/50 minutes; pH change (to 7.0, 7.5, and 8.0); addition of flocculant (0, 30, and 60 ppm Aluminum polychloride or APC - "Panclar P-1010"), and clarifier aid (0, 2, or 4 ppm of positively charged polyelectrolyte - "Magnafloc LT-27"). The decantation time was 45 minutes and the supernatant liquid was removed with a vacuum pump. The treatments were defined using the Response Surface Methodology and were submitted to physicochemical analysis for turbidity (%), total polysaccharide content (µg.mL-1), dextran content (µg.mL-1), and sensory analysis (acceptance test) for the attributes of color, appearance, and turbidity. It was concluded that the addition of 60 ppm APC, pH 8, and 0 ppm polyelectrolyte represented the best treatment to obtain a low polysaccharide content, 90% turbidity, and high scores for color, appearance, and turbidity. The beverage was sensorially well accepted by consumers.

Effect of drying method on the adsorption isotherms and isosteric heat of passion fruit pulp powder

The sorption behavior of dry products is generally affected by the drying method. The sorption isotherms are useful to determine and compare thermodynamic properties of passion fruit pulp powder processed by different drying methods. The objective of this study is to analyze the effects of different drying methods on the sorption properties of passion fruit pulp powder. Passion fruit pulp powder was dehydrated using different dryers: vacuum, spray dryer, vibro-fluidized, and freeze dryer. The moisture equilibrium data of Passion Fruit Pulp (PFP) powders with 55% of maltodextrin (MD) were determined at 20, 30, 40 and 50 ºC. The behavior of the curves was type III, according to Brunauer's classification, and the GAB model was fitted to the experimental equilibrium data. The equilibrium moisture contents of the samples were little affected by temperature variation. The spray dryer provides a dry product with higher adsorption capacity than that of the other methods. The vibro-fluidized bed drying showed higher adsorption capacity than that of vacuum and freeze drying. The vacuum and freeze drying presented the same adsorption capacity. The isosteric heats of sorption were found to decrease with increasing moisture content. Considering the effect of drying methods, the highest isosteric heat of sorption was observed for powders produced by spray drying, whereas powders obtained by vacuum and freeze drying showed the lowest isosteric heats of sorption.

Comparison of methodologies for moisture determination on dried bee pollen samples

Bee pollen moisture value is one of the quality parameters for this product. Some countries such as Argentina, Brazil, Bulgaria, Poland and Switzerland have bee pollen regulations on quality parameters, but these are not clear regarding which method should be used for moisture determination. The aim of this paper was to compare six methods of moisture determination in dried bee pollen samples. The methods were: conventional oven at 100 °C, vacuum oven at 70 °C, desiccator with sulfuric acid, drying out process with infrared light at 85 °C, lyophilization and Karl Fisher's method. Based on the results, the best methods for moisture determination of bee pollen were the drying process with infrared and the lyophilization, since these have shown lower moisture values.

Jaboticaba peel for jelly preparation: an alternative technology

The peel of jaboticaba is attractive regarding its nutritional, functional and sensory aspects. However, its use for consumption is still restricted due to the need of technological development in order to obtain processed preparations for its inclusion in the human diet. The purpose of this study was to produce jelly using the peel of jaboticaba and to characterize it chemically and sensorially. Diferent formulations were prepared, all with 50% of sugar and with different proportions of peel, pulp and pectin. The formulations, which were tested for preference, were the following: F1a (80% of peel, 20% of pulp and 0.5% of pectin) and F3b (50% of peel, 50% pulp and 1.0% of pectin). These formulations showed chemical composition of 216.44 mg phenolic compounds, 148.00 mg gallic acid.100 g-1, 10.42 mg flavonoids, and 12.10 mg catechin.100 g-1, and 80% acceptability index. The peel presented higher levels of nutrients than the pulp, especially as source of fiber, carbohydrates and natural pigments. Results indicated the feasibility of technological nutritional harnessing of the jaboticaba peel in obtaining jelly. The results also indicated good sensory and nutritional characteristics, acceptability, and antioxidant properties of natural pigments.

Fish crackers development from minced fish and starch: an innovative approach to a traditional product

This study aimed to develop sensory acceptable, high nutritional value fish crackers that could be kept at room temperature for 180 days. Minced fish of different low-value species was the raw material employed to produce two types of fish crackers: a) the traditional keropok cracker, which was expanded by deep frying; and b) a low-fat fish cracker, expanded by microwave cooking. The protein content of the fried fish crackers (FFCs) and that of the microwaved fish crackers (MFCs) were high (10.86 and 14.70%, respectively). The essential amino acid contents of the two types of fish cracker were above the FAO requirements for adults, and the lysine content was above the requirements for children. Sensory analysis, performed by adult panelists, resulted in a general level of acceptability of 90% for the MFCs and of 97% for the FFCs. Vacuum packaging maintained microbiological and physicochemical properties for a storage period of 180 days at room temperature.