Latest Research on Bioresource Engineering : Nov 2020

Strategic Themes in Agricultural and Bioresource Engineering in the 21st Century

During the 20th century, agricultural engineering became a really multidisciplinary field of science. Besides traditional mechanical engineering, fundamental developments in microelectronics, systems and control engineering, chemical engineering and physics have opened wide perspectives for agricultural engineering. During the last century, agricultural engineering has effected major changes in agriculture with regard to labour productivity and specialization in the different sectors of plant production and livestock production. Public concern for environmental issues, e.g. emissions of volatile compounds, water pollution through plant nutrients and agrochemicals, has resulted in research and technology development in the field of environmental engineering. In developing activities for more sustainability in production, agricultural enterprises have to reclaim the trust of society and earn ‘the licence to produce’! Agricultural engineers have the chances to contribute in this process. They must be also aware that new technologies and techniques require thorough full technology assessment procedure to make clear aspects of acceptability to different groups in the community. To achieve optimal results for agribusiness and the society, the expertise of agricultural engineers must be integrated with expertise from the biological and socio-economic sciences. In agricultural engineering, a dynamic balance between economy, technology and ecology must always be found in order to satisfy the requirements of government and the changing preferences of consumers. Recognition of trends in the society and networking and participation in debates are important activities for agricultural engineers in the 21st century. ‘Breakthrough’ technologies are needed for agricultural enterprises to meet the increasing list of standards and norms, for example in the areas of energy, animal welfare, product quality, water and volatile emissions.

As this was the case in the last century, agricultural engineering has therefore to keep pace with trends in science and technology, e.g. fundamental developments in the information and communication technology, biotechnology, materials technology, microelectronics and mechatronics. Technology watch, networking and cooperation are key words for agricultural engineers.

In line with these challenges, strategic themes for the agricultural engineering science are: the concepts for sustainable bioproduction systems in the greenhouse and livestock sector; the further progress in precision agriculture; the use of biomass and wastes as energy sources: electronic communication with models and databases without human interference (green net); and innovative measurement and biomonitoring systems. [1]

Reversegenetic approach to verify physiological roles of rice phytoalexins: characterization of a knockdown mutant of OsCPS4 phytoalexin biosynthetic gene in rice

A variety of labdane‐related diterpenoids, including phytocassanes, oryzalexins and momilactones, were identified as phytoalexins in rice (Oryza sativa L.). Momilactone B was also isolated as an allelochemical exuded from rice roots. The biosynthetic genes of these phytoalexins have been identified, including six labdane‐related diterpene cyclase genes such as OsCPS2, OsCPS4, OsKSL4, OsKSL7, OsKSL8 and OsKSL10. Here we identified an OsCPS4 knockdown mutant, cps4‐tos, by screening Tos17 mutant lines using polymerase chain reaction. OsCPS4 encodes a syn‐copalyl diphosphate synthase responsible for momilactones and oryzalexin S biosynthesis. Because Tos17 was inserted into the third intron of OsCPS4, the mature OsCPS4 mRNA was detected in the cps4‐tos mutant as well as the wild type. Nevertheless, mature OsCPS4 transcript levels in the cps4‐tos mutant were about one sixth those in the wild type. The cps4‐tos mutant was more susceptible to rice blast fungus than the wild type, possibly due to lower levels of momilactones and oryzalexin S in the mutant. Moreover, co‐cultivation experiments suggested that the allelopathic effect of cps4‐tos against some kinds of lowland weeds was significantly lower than that of the wild type, probably because of lower momilactone content exuded from cps4‐tos roots. A reverse‐genetic strategy using the cps4‐tos mutant showed the possible roles of momilactones not only as phytoalexins but also as allelopathic substances. [2]

Pulsed electric field treatment of carrots before drying and rehydration

BACKGROUND: In this study the effects of pulsed electric field (PEF) pretreatment were evaluated during drying and rehydration of carrots. Carrots pretreated with an electric field intensity of 1 kV cm−1 (capacitance 0.5 µF, 20 pulses) or 1.5 kV cm−1 (capacitance 1 µF, 20 pulses) as well as blanched (100 °C, 3 min) carrots were used for the study. Following pretreatment, samples were oven dried at 70 °C and then rehydrated in distilled water (1:30 w/v) at room temperature (24 ± 1 °C).

RESULTS: PEF pretreatment increased the drying rate of carrots. However, the rehydration rate of PEF‐pretreated carrots was lower than that of blanched carrots. There were no colour differences between PEF‐pretreated and blanched carrots before drying and after rehydration. In terms of texture, PEF‐pretreated carrots were firmer than blanched carrots. PEF pretreatment reduced the activity of peroxidase by 30–50%, while blanching completely inactivated the enzyme (>95%).

CONCLUSIONS: Overall, the results suggest that PEF could be an effective pretreatment during drying and rehydration of carrots. Copyright © 2009 Society of Chemical Industry. [3]

In vitro Starch Digestibility and Nutritional Composition of Improved Rice Varieties from Cameroun

Aims: Resistant starch (RS), kinetics of starch digestion, predicted glycemic index (pGI) and nutritional composition were determined in two improved rice varieties from Cameroun.

Place and Duration of Study: Department of Bioresource Engineering, McGill University, Canada between December 2012 and March 2013.

Methodology: Non-parboiled and parboiled samples of TOX 3145 and NERICA-3 varieties were involved in this study. An in vitro enzymatic starch digestion method was applied to measure starch digestibility parameters. Standardized methods were adopted for proximate and mineral contents evaluation.

Results: The parboiled samples had significantly higher (P<0.05) resistant starch (8.35 – 11.07%) than the non-parboiled samples (3.81 – 4.84%). The values for pGI among samples ranged from 57.57 to 67.78%. Significantly higher values for protein, phosphorus and potassium were found among the parboiled samples (P<0.05). Nutritional composition was positively related to RS while pGI had inverse relationship with protein, ash, fat, phosphorus, potassium and RS.

Conclusion: Starch digestibility of these rice varieties was associated to their nutritional composition. [4]

Design and Evaluation of Livestock Dewatering Machine

A livestock dewatering machine was designed, fabricated and evaluated to improve on-farm management of animal waste. This is in response to the need to reduce and eliminate the many challenges of improper waste handling in livestock production farms in Nigeria. The machine consists of a hopper, gear rack, shaft, speed reducer, ball bearings, screen, and discharge chute. The machine is manually operated by cranking of the handle which transmits torque to the shaft and thus set the rack in motion. The rack compresses the slurry against the wall of hard casing, and the liquid is separated from the waste and let out through the screen at the bottom of the casing, leaving the dewatered waste to escape through the discharge chute. Particle size distribution analysis guided the choice of screen size of 2 mm diameter. The machine was tested with pig dung, and it gave a throughput capacity of 472.75 kh/hr and a separating efficiency of 9%. [5]


Reference

[1] Jongebreur, A.A., 2000. Strategic themes in agricultural and bioresource engineering in the 21st century. Journal of Agricultural Engineering Research, 76(3), pp.227-236.

[2] Toyomasu, T., Usui, M., Sugawara, C., Otomo, K., Hirose, Y., Miyao, A., Hirochika, H., Okada, K., Shimizu, T., Koga, J. and Hasegawa, M., 2014. Reverse‐genetic approach to verify physiological roles of rice phytoalexins: characterization of a knockdown mutant of OsCPS4 phytoalexin biosynthetic gene in rice. Physiologia plantarum, 150(1), pp.55-62.

[3] Gachovska, T.K., Simpson, M.V., Ngadi, M.O. and Raghavan, G.S.V., 2009. Pulsed electric field treatment of carrots before drying and rehydration. Journal of the Science of Food and Agriculture, 89(14), pp.2372-2376.

[4] M. Odenigbo, A., Ndindeng, S., A. Nwankpa, C., Woin, N. and Ngadi, M. (2013) “In vitro Starch Digestibility and Nutritional Composition of Improved Rice Varieties from Cameroun”, European Journal of Nutrition & Food Safety, 3(4), pp. 134-145. doi: 10.9734/EJNFS/2013/5096.

[5] Igbozulike, A. O. and Bill, U. D. (2015) “Design and Evaluation of Livestock Dewatering Machine”, Current Journal of Applied Science and Technology, 10(6), pp. 1-6. doi: 10.9734/BJAST/2015/17858.

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