Nutritional value of bee-collected pollens of hardy kiwi, Actinidia arguta (Actinidiaceae) and oak, Quercus sp. (Fagaceae)

Abstract

Bee-collected pollens have gained attention as natural dietary supplement for human nutrition over the honeybee feed, and become important commercial hive products for beekeepers. Oak trees, Quercus sp. (Family: Fagaceae) and hardy kiwi, Actinidia arguta (Family: Actinidiaceae) are important pollen sources for honey bees. During collection and storage through the addition of nectar and salivary secretions the chemical composition of pollen is changed. We analyzed nutrient contents of bee collected oak and hardy kiwi pollens and compared with recommended requirement of essential amino acids for honey bee brood development. The results revealed that protein content was found 23.2% for oak and 26.5% for hardy kiwi pollen. All the determined essential amino acid contents of both oak and kiwi pollen satisfied the minimum individual amino acid requirement of honey bee. Threonine was present in marginal level in hardy kiwi pollen. Fat content of oak and hardy kiwi pollen were found 7 and 4.5% respectively. The higher value of polyunsaturated fatty acid/saturated fatty acid - stearic acid, lower AI and TI value, presence of essential fatty acid n-3 linolenic acid indicated these pollens as superior sources of fat. The most abundant mineral was found potassium in both the pollens followed by phosphorus. In contrast sodium content was found very less. In vitro digestibility of oak and kiwi pollen were found 69.5 and 37.8% suggesting the difficulty of nutrient uptake directly from pollen grains.