Potential benefits of near critical and supercritical pre-treatment of lignocellulosic biomass towards anaerobic digestion.

Vegetable crop residues, such as sugarcane bagasse (SCB), despite their limited biodegradability, are potential materials for anaerobic processes because of their low cost, high availability, and sugar content. The difficulty of biodegrading this type of material is primarily related to its chemical composition and to the complex interactions between its compounds (cellulose, hemicelluloses, and lignin). Thus, the following supercritical and near critical carbon dioxide (CO2) pre-treatments were evaluated with and without the addition of sodium hydroxide (NaOH): (i) 40°C/70 kgf·cm-2; (ii) 60°C/200 kgf·cm-2; and (iii) 80°C/200 kgf·cm-2, aiming to enhance the anaerobic biodegradability of SCB. The methanogenic production of SCB increased in all cases in which the material was pre-treated, except the case in which NaOH was used together with a high temperature. The condition using CO2 at 60°C/200 kgf·cm-2 was highlighted with a lignin removal of 8.07% and an accumulated methane production of 0.6498 ± 0.014 LN (273.15K, 1.01325 × 105 Pa), 23.4% higher than the value obtained with the untreated material. This condition also showed the highest net energy at the energy balance that was calculated for comparison with the tested conditions. The results showed that pre-treatments with near critical and supercritical fluids have the potential to reduce structural obstacles of lignocellulosic materials and to enhance their anaerobic biodegradability.

Predicting pork quality using Vis/NIR spectroscopy.

Visible and near-infrared reflectance spectroscopy (Vis/NIRS) was used to predict the ultimate pH (pHu), color, intramuscular fat (IMF) and shear force (WBSF) of pork samples and to build classifiers capable of categorizing the samples by tenderness (tender or tough) and juiciness (juicy and dry). Spectra were collected from 400 to 1495nm, and 200 data points were generated for every sample (n=134). Sixty-seven percent of the sample set was used for calibration, and 33% was used for validation. Partial least squares (PLS) calibration models were developed for each characteristic measured. A coefficient of determination (R(2)) and residual prediction deviation (RPD) were used to evaluate the accuracy of the calibration models. The pHu and color prediction models developed in this study fit this classification, indicating that these predictive models can be used to predict quality traits of intact pork samples. The Vis/NIRS offered great potential for correctly classifying pork Longissimus into two tenderness and two juiciness classes.

Castor Bean Cake Protein-based Biodegradable Films: Gallic Acid Effect

Abstract: The objective of this work was to evaluate the effect of gallic acid (GA) concentration on some physical properties and biodegradability of films produced with proteins extracted from the castor bean cake. The films, prepared by the casting technique, showed homogeneous and brownish appearance. As the GA concentration increased (from 0 to 10 g/100 g protein), the films gradually became darker and more opaque; while the gloss had few significant differences. Solubility, tensile strength and elasticity modulus values of films varied due to changing concentrations of gallic acid. Elongation at break and water vapor permeability values did not have significant changes. A 60% mineralization value of the film containing GA was obtained at 21 days, evidencing its biodegradability. These dark and opaque films could be used in agriculture, specifically in seedling bags as the dark color decrease the incidence of light, preventing root weakening, and the seedlings can be transplanted directly without removal of the film.

Efeitos do incremento de fibra dietética sobre digestibilidade, desempenho e características de carcaça: II: fêmeas suínas em pré-puberdade e puberdade / Effects of increasing dietary fiber on digestibility, performance and carcass characteristics: II: prepuberty and puberty gilts

Fêmeas suínas destinadas à reprodução devem seguir um plano de restrição alimentar objetivando controlar excessiva ingestão calórica. Emprego de alimentos volumosos, devido ao seu alto teor de fibra, fornece menor aporte de energia para suínos. Esta estratégia alimentar contorna o problema da acumulação excessiva de gordura corporal. Objetivando estudar estes aspectos, fêmeas pré-púberes e púberes foram alimentadas com rações isoenergéticas e isoprotéicas contendo 0; 6,6; 13,2 e 19,8% de fibra em detergente neutro (FDN), obtidas pela inclusão de feno de coast-cross. Vinte marrãs mestiças foram empregadas em um delineamento experimental de blocos casualizados, que durou 97 dias. Após, os animais foram sacrificados. O incremento de FDN na ração diminuiu o ganho de peso linearmente (0,675;0,607; 0,525; 0,483 g/dia); o peso corporal ao primeiro cio útil (118,0; 114,0; 102,2; 98,2 kg) e piorou a conversão alimentar (3,6; 4,0; 4,7; 5,3). Observou-se resposta quadrática na espessura de toucinho (3,28; 3,34; 2,82; 1,74 cm). Não houve efeito sobre a idade de ocorrência do primeiro cio útil (203 dias) e no rendimento de carcaça quente; entretanto, foram obtidas respostas quadráticas para o rendimento de carcaça fria (79,79; 80,24; 79,58; 77,40%) e de carne magra (54,45; 54,35; 55,51; 58,31%). Níveis crescentesde FDN reduziram linearmente os coeficientes de digestibilidade da matéria seca (76,23; 67,23; 55,83;55,73%) e da fibra em detergente neutro (56,63; 44,24; 34,17; 39,12%); houve respostas quadráticas para a proteína bruta (72,16; 64,46; 53,52; 62,74 %) e energia bruta (71,95; 61,23; 49,21; 53,81%). A condição corporal necessária para fêmeas reprodutoras não foi prejudicada pelo oferecimento de ração fibrosa durante as fases de pré-puberdade e puberdade.

Female pigs that are intended to be used as sows have to follow a dietary plan that restricts caloric intake.Roughages due to their high content of fiber are low energy sources for swine. This feeding strategy getsaround the excessive body fat accumulation. Aiming to study these aspects, prepuberty and puberty giltswere fed isoenergetic and isoproteic rations containing 0; 6.6; 13.2 and 19.8% of neutral detergent fiber (NDF),obtained with the inclusion of coast-cross hay. Twenty crossbred gilts were assigned to a randomized blockdesign experiment which lasted 97 days. Then, the animals were slaughtered. Increment of NDF reducedlinearly body weight gain (0.675; 0.607; 0.525; 0.483 g/day); body weight on first physiological heat onset(118.0; 114.0; 102.2; 98.2 kg) and worsened feed conversion (3.6; 4.0; 4.7; 5.3). It was observed a quadraticresponse on the backfat thickness (3.28; 3.34; 2.82; 1.74 cm). There was no effect over the age of firstphysiological heat onset (203 days) and hot carcass yield; however, quadratic response for cold carcass yieldwas obtained (79.79; 80.24; 79.58; 77.40%) and lean meat yield (54.45; 54.35; 55.51; 58.31%). Increasing contentof NDF reduced linearly dry matter digestibility (76.23; 67.23; 55.83; 55.73%) and NDF digestibility (56.63;44.24; 34.17; 39.12%); there were quadratic responses to crude protein (72.16; 64.46; 53.52; 62.74%) and crudeenergy digestibilities (71.95; 61.23; 49.21; 53.81%). Gilts body condition was not affected by continuousoffering of fibrous ration during prepuberty and puberty phases.

Lignin concentration in oat (Avena byzantina L. ) aerial part as measured by four analytical methods

The current analytical methods to quantify lignin in forages are not satisfactory. A spectrophotometric method, the acetyl bromide lignin(ABL), has been employed to determine lignin concentration in forages; however, it suffers from the lack of an ideal standard with which the optical density readings of samples are compared to. A lignin, extracted from the plant with a solution of acidic dioxane, was employed to build a calibration curve for this method. This procedure was then compared with other methods (acid detergent lignin - ADL, Klason lignin – KL and potassium permanganate lignin – PerL) to determine lignin content on different fractions (stem, leaf and whole plant) of eight oat cultivars (Avena byzantina L.). There was no agreement among the four methods. In general, ABL and KL methods yielded thehighest values while ADL method yielded the lowest, particularly for the young plants. Lignin concentration was higher in the stem fractionas compared to leaf. It was detected influence of maturity stage in the investigated samples. It is concluded that the ABL method employingas standard lignin extracted with acidic dioxane has potential to be employed as a method to determine lignin concentration.

Os métodos analíticos para quantificar a concentração de lignina atualmente em uso não se tem mostrado satisfatórios. Um método espectrofotométrico, a lignina brometo de acetila (LBA) tem sido empregado para determinar o teor de lignina em plantas forrageiras; entretanto, padece da inexistência de um padrão de referência ideal, com o qual as leituras de densidade óptica das amostras são comparadas. Uma lignina, extraída da planta com solução ácida dedioxano, foi empregada para a construção de uma curva de calibração para o método em questão. Este procedimento foi comparado com outros métodos (lignina detergente ácido - LDA, lignina Klason –LK e lignina permanganato de potássio - LPer) na estimativa do teor de lignina em diferentes frações vegetais (caule, folha e parte aérea) de oito cultivares de aveia (Avena byzantina L.). Não houve concordância de valores entre os quatro métodos analíticos. Num âmbito geral,LBA e LK forneceram as maiores estimativas enquanto a LDA resultounos menores valores, particularmente nas amostras de plantas mais jovens. A concentração de lignina foi mais elevada na fração caule do que na folha. Foi detectado efeito da maturidade nas amostras analisadas. Conclui-se que o método LBA usando como padrão de referência a lignina extraída com dioxano ácido tem potencial para ser empregado nas determinações dos teores de lignina.