Pigeonpea Grain Research Articles

Pretreatment of pigeonpea grain for improvement of dehulling characteristics

Summary Pigeonpea grain (c.v. C11) was used for optimization of dehulling pretreatments. Treatments applied for dehulling were soaking in urea solution and hot milling. Second order polynomial equations were developed to describe a dehulling index and dehulling time. Response surface methodology was also used. Treatment with urea solution was applied to both nonscarified and scarified grain. Different concentrations, solution‐to‐grain ratios and duration of treatments were tested in five levels as independent factors in the first set of experiments. In the second set, hot milling, heating time and heating temperature were factors in five levels. Hot milling was followed by optimized treatment with urea solution. The levels of these factors were optimized to give a maximum dehulling index and minimum dehulling time, this would yield the maximum product recovery and reduce grain scouring. The results revealed that hot milling after urea treatment of scarified grain increased the dehulling index by about 11% and, consequently, reduced dehulling time by approximately 65% when compared with the treatment followed in commercial mills. This subsequently increased the product recovery and intact pearled grain by about 19 and 23%, respectively.

The effect of pre‐treatment on the strength and dehulling properties of pigeonpea grain

Summary The effect of different pre‐treatments, i.e. grain scarification, chemical treatment and hot milling, on the strength and dehulling properties of pigeonpea grain was studied by measurement of the forces required for removal of the seed coat from cotyledons and of cotyledons from each other. The dehulling index, dehulling time, product recovery and amount of intact pearled grain were determined after dehulling the pre‐treated grain. The results revealed that a significant (P < 0.05) reduction in seed coat adhesion could be obtained by urea treated scarified grain when hot milled. This, in turn, increased the dehulling index for both the cultivars studied, with subsequent reduction in dehulling time, resulting in a high product recovery of about 81%, and an increased quantity of intact pearled grain of about 39%.

Aspectos químicos e bioquímicos de leguminosas enlatadas em diferentes estádios de maturação

Este trabalho teve como objetivo estudar a composição química e aspectos bioquímicos dos grãos de soja cultivar IAC PL-1 e de guandu cultivar IAC Fava Larga, crus e pós-enlatamento em diferentes estádios de maturação avaliando os efeitos do processamento sobre os grãos dos dois cultivares. A composição química dos grãos crus , principalmente no último estádio verde, e na maturação de colheita foi de modo geral semelhante. O enlatamento conservou 95% e 98% do total das proteínas dos grãos de soja e guandu, respectivamente. Nos enlatados de soja obteve-se a inativação da atividade de lectinas. Os processamentos térmicos utilizados para os enlatamentos, 121ºC por 6 a 7 minutos para a soja e 5 a 6 minutos para o guandu foram suficientes para eliminar 83% da atividade dos inibidores de tripsina da soja e do guandu. A digestibilidade da proteína do guandu enlatado (62%) foi inferior em relação à soja enlatada (78%). Com exceção do ácido glutâmico, prolina, lisina e histidina, os demais aminoácidos do grão de soja enlatado colhido no 64º DAF tiveram seus conteúdos iguais aos enlatados do 85º DAF pós-armazenados e pós-macerados. Os teores de aminoácidos dos grãos de guandu enlatados no 62º DAF, com exceção do ácido glutâmico e fenilalanina, foram iguais àqueles presentes na última colheita (92º DAF). A metionina disponível no grão de soja não se modificou com a evolução da maturação, porém a do guandu se elevou no 92º DAF e o processo de enlatamento reduziu a metionina disponível da soja apenas no 55º e 64º DAF e do guandu no 57º e 92º DAF. Rafinose e estaquiose nos grãos de soja estão mais elevadas no estádio verde, e nos grãos de guandu, apenas a estaquiose está mais elevada no estádio verde. O processo de enlatamento provocou um pequeno decréscimo nestes dois açúcares da soja e guandu nos dois últimos estádios de maturação estudados.

Shear forces for dehulling, splitting and breaking raw and pretreated pigeonpeas

SummaryAn instrument to measure the seed coat adhesion, cotyledon adhesion and shear strength of pigeonpea grain was constructed using a peizo‐electric transducer. Urea was applied to scarified and non‐scarified grain and part was then heat treated. Seed coat adhesion was slightly reduced by scarification of grain and further reduced by urea plus heat treatment. Cotyledon adhesion was slightly reduced by urea plus heat but shear strength was unaffected. Pretreatments may lead to an improved quality product (good quality splits and less breakage). The instrument may be useful in assessing improved cultivars.

Dry matter yield and chemical composition of pigeon pea ( C. cajan) leaf meal and the nutritive value of pigeon pea leaf meal and grain meal for laying hens

Three studies were conducted to determine: (1) the yield of leaf meal of pigeon pea in the southeastern agricultural zone of Nigeria; (2) the value of pigeon pea leaf meal (PPLM) as a feed ingredient and egg yolk colouring agent in layers' diets; (3) the value of pigeon pea grain meal (PPGM) as a protein and energy source for layers. Dry matter yields of PPLM were 2.30, 2.36 and 2.68 t ha −1 for 4-, 6- and 8-week cutting intervals, respectively. Crude protein content increased with more frequent cutting intervals and crude fibre with less frequent cutting intervals. Up to 7.5% PPLM in diets did not adversely affect layer performnce, but 10% was needed to give a yolk colour score of 8 on the Roche colour fan in white maize-based layers' diets. At dietary levels >20%, PPGM depressed feed intake and egg production.

Kinetics of Water Sorption by Soybean and Pigeonpea Grains

ABSTRACTKinetics of liquid water sorption by soybean (Glycine max) and pigeonpea (Cajanus cajan) seeds was studied at several temperatures. The data could be accurately correlated in terms of an empirical model involving a single rate constant. The temperature dependence of the rate constant followed Arrhenius relation. Swelling of grains due to water sorption was slightly less than the volume of water imbibed. This loss related to the energy of activation of the water sorption process.

Effect of Soil Mineral N Levels and Inoculation on Nodulation, Nitrogenase Activity, and Grain Yield of Pigeon Pea1

AbstractSince pigeon pea [Cajanus cajan L. (Millsp.)] has a considerable potential as a tropical legume, intensive research in the Caribbean is being undertaken with a view to increase production. There is a scarcity of information on the effectiveness of Rhizobium of the pigeon pea to fix atmospheric N and to meet the N needs of the crop. Moreover, conflicting results have been reported on the effect of fertilizer N on grain yield, presumably because of variable mineral N levels in soil. Therefore the present investigation was designed to study the effect of changes in soil mineral N levels (brought about initially by incorporation of coconut fibre and bagasse with soil at the rate of 25 metric tons/ha each) and five Rhizobium strains (two local, UWI 10004 and UWI 10013, and three exotic, iCPE(a), CB756 and CIAM/1001) on nodulation, nitrogenase activity and grain yield of the crop. Greenhouse and field experiments were conducted on a River Estate Loam, a fluventic eutropept, at the University Field Station, Trinidad. The results showed that the incorporation of coconut fibre and begasse reduced soil mineral N levels through immobilization and led to early nodule formation and nitrogenase activity. Although the incorporation of coconut fibre increased plant shoot weight after 14 weeks growth, that of bagasse immobilized so much mineral N (from initial level of 50 ppm N to 6 ppm N at 7 weeks after application) that plants were N starved. The dry pod yield was increased by all Rhizobium strains. However the grain yield was significantly increased by the exotic strains, iCPE(a) and CIAM/1001. Thus, by manipulating soil mineral N levels and by using effective Rhizobium strains, the pigeon pea grain yields can be increased.