Agriculture and Agri-Food Canada

About: Agriculture and Agri-Food Canada is a facility organization based out in Ottawa, Ontario, Canada. It is known for research contribution in the topics: Population & Soil water. The organization has 10921 authors who have published 21332 publications receiving 748193 citations. The organization is also known as: Department of Agriculture and Agri-Food.

Dietary sources of lutein and zeaxanthin carotenoids and their role in eye health.

Abstract: The eye is a major sensory organ that requires special care for a healthy and productive lifestyle Numerous studies have identified lutein and zeaxanthin to be essential components for eye health Lutein and zeaxanthin are carotenoid pigments that impart yellow or orange color to various common foods such as cantaloupe, pasta, corn, carrots, orange/yellow peppers, fish, salmon and eggs Their role in human health, in particular the health of the eye, is well established from epidemiological, clinical and interventional studies They constitute the main pigments found in the yellow spot of the human retina which protect the macula from damage by blue light, improve visual acuity and scavenge harmful reactive oxygen species They have also been linked with reduced risk of age-related macular degeneration (AMD) and cataracts Research over the past decade has focused on the development of carotenoid-rich foods to boost their intake especially in the elderly population The aim of this article is to review recent scientific evidences supporting the benefits of lutein and zexanthin in preventing the onset of two major age-related eye diseases with diets rich in these carotenoids The review also lists major dietary sources of lutein and zeaxanthin and refers to newly developed foods, daily intake, bioavailability and physiological effects in relation to eye health Examples of the newly developed high-lutein functional foods are also underlined

The soil carbon dilemma: Shall we hoard it or use it?

Abstract: Rapidly rising concentrations of atmospheric CO2 have prompted a flurry of studies on soils as potential carbon (C) ‘sinks’. Sequestering C in soils is often seen as a ‘win–win’ proposition; it not only removes excess CO2 from the air, but also improves soils by augmenting organic matter, an energy and nutrient source for biota. But organic matter is most useful, biologically, when it decays. So we face a dilemma: can we both conserve organic matter and profit from its decay? Or must we choose one or the other? In this essay, I contemplate the merits, first of building soil C and then of decaying (losing) it, partly from a historical perspective. I then consider the apparent trade-off between accrual and decay, and reflect on how the dilemma might be resolved or assuaged. These fledgling thoughts, offered mostly to stir more fruitful debate, include: finding ways to increase C inputs to soil; seeking to optimize the timing of decay; and understanding better, from an ecosystem perspective, the flows of C, rather than only the stocks. Carbon sequestration is a sound and worthy goal. But soil organic matter is far more than a potential tank for impounding excess CO2; it is a relentless flow of C atoms, through a myriad of streams—some fast, some slow—wending their way through the ecosystem, driving biotic processes along the way. Now, when we aim to regain some of the C lost, we may need new ways of thinking about soil C dynamics, and tuning them for the services expected of our ecosystems. This objective, perhaps demanding more biology along with other disciplines, is especially urgent when we contemplate the stresses soon to be imposed by coming global changes.

Regulated deficit irrigation for crop production under drought stress. A review

Abstract: Agriculture consumes more than two thirds of the total freshwater of the planet. This issue causes substantial conflict in freshwater allocation between agriculture and other economic sectors. Regulated deficit irrigation (RDI) is key technology because it helps to improve water use efficiency. Nonetheless, there is a lack of understanding of the mechanisms with which plants respond to RDI. In particular, little is known about how RDI might increase crop production while reducing the amount of irrigation water in real-world agriculture. In this review, we found that RDI is largely implemented through three approaches: (1) growth stage-based deficit irrigation, (2) partial root-zone irrigation, and (3) subsurface dripper irrigation. Among these, partial root-zone irrigation is the most popular and effective because many field crops and some woody crops can save irrigation water up to 20 to 30 % without or with a minimal impact on crop yield. Improved water use efficiency with RDI is mainly due to the following: (1) enhanced guard cell signal transduction network that decreases transpiration water loss, (2) optimized stomatal control that improves the photosynthesis to transpiration ratio, and (3) decreased evaporative surface areas with partial root-zone irrigation that reduces soil evaporation. The mechanisms involved in the plant response to RDI-induced water stress include the morphological traits, e.g., increased root to shoot ratio and improved nutrient uptake and recovery; physiological traits, e.g., stomatal closure, decreased leaf respiration, and maintained photosynthesis; and biochemical traits, e.g., increased signaling molecules and enhanced antioxidation enzymatic activity.

Optimization of Extraction of Anthocyanins from Black Currants with Aqueous Ethanol

Abstract: Extraction of anthocyanins from black currants using aqueous ethanol was optimized for yield and antioxidant activity. The process variable having the most effect on the extraction was the solvent to solid ratio, which increased phenolic extraction in the whole range from 0 to 19 L/kg. Total phenolics increased with ethanol concentration up to a maximum at about 60% and then decreased with further increase in solvent concentration irrespective of the solvent to solid ratio. Temperature only affected the extraction of anthocyanins. Increasing the temperature beyond 30 to 35 °C resulted in degradation of anthocyanins and reduction of yields. Variation in extract composition was not sufficiently large to affect antioxidant activity.