Coffee contains several nutrients that have proven key to combating or protecting against some well-known diseases. Typically, a single cup of freshly brewed coffee contains Riboflavin, Pantothenic Acid, Manganese & Potassium and Magnesium & Niacin.
Coffea Nutrient Absorption
It is no surprise that cultivated plants require numerous macro and micro nutrients in order to maximise their growth and production. Given that the coffee plant (Coffea species) is a nutrient-intensive plant then surely it must follow that much of these nutrients find their way to the coffee bean itself?
Nutrient requirement in the early stages of Coffea growth is fairly minimal. The nutritional demands increase significantly after about 24-30 months after planting with the plant requiring roughly 2-3 times more than the initial phases of growth. The growth of the flower buds on the coffee plant is directly related to coffee bean growth, therefore, a lack of the required nutrients adversely affects the buds and thus the coffee bean growth.
Scientific studies have shown that the nutritional needs of the coffee plant is much higher at the 55 month mark than at the 31 month mark. In a representative sample study, the average coffee production at 55 months after planting was 4650kg per hectare. whereas, at 31 months after planting, coffee production was only 1248kg per hectare. This clearly shows that the coffee beans are the main demand driver of nutrients in the coffee plant given that approaching the 55 month mark is the optimal coffee fruit production phase.
Nutrients in the Coffee Bean
Nitrogen is the most required nutrient of the coffee plant and, when properly nourished, is present in the plant by 26-30kg of dry matter. The main purpose of nitrogen in the plant is the formation of amino acids then ultimately form proteins. This process is essential to ensure vegetative growth and coffee fruit filling. Basically, healthy levels of Nitrogen in the coffee plant results in far healthier coffee beans growth and quality. It should be noted, however, that excessive levels of nitrogen can attract pests such as the 'leaf miner' and 'green scale'.
So how much of the attracted nutrients to the plant actually reach the coffee bean itself and remain after processing? In truth, due to the demanding nature of the coffee plant for various nutrients coupled with the importance of the these nutrients in order to grown and develop healthier coffee fruits, the coffee bean itself does hold many macro & micro nutrients even after processing. These nutrients range from nitrogen, calcium & magnesium to potassium, phosphorus &| aluminium, to name a few.
The longer one roasts a coffee bean the greater content of the beans natural elements are removed. This a mainly due to the drying out process involved with roasting the coffee bean. Although other elements do form with roasting duration, some good and some not so good, the natural nutrient levels of the coffee bean is far higher with a lighter roast.
Source: Coffee: Production, Quality & Chemistry