Effect of Alkaline Treatment on Characteristics of Bio-Calcium and Hydroxyapatite Powders Derived from Salmon Bone

Abstract

Alkaline treatment has been extensively implemented in the extraction process of hydroxyapatite (HAp) extraction from various kinds of bio-materials, such as animal bone and scales. The main purpose of such treatment is to remove proteinaceous substances from raw materials. The influence of the alkaline treatment that could alter not only the organic contents but also chemical composition—specifically the Ca/P mole ratios of bio-calcium, HAp, and the biphasic apatite powders derived from salmon bone, a by-product from the salmon industry—was investigated. Both HAp and biphasic apatite powders were obtained from the calcination of bio-calcium powders with and without alkaline treatment, respectively. An X-ray diffraction analysis confirmed the presence of hydroxyapatite and β-tricalcium phosphate (β-TCP) in the calcined bone powder without alkaline treatment while only a single phase of hydroxyapatite was observed in the alkaline-treated sample. Calcium and phosphorus contents were measured by an inductively coupled plasma optical emission spectrometer (ICP-OES). A variation of Ca/P ratios was observed among all samples, depending on the chemical and heat treatment conditions. Organic molecules, such as protein, fat, hydroxyproline, and TBARS, were significantly lowered in bio-calcium powders with the alkaline treatment. This work represents important research on chemical treatment prior to the raw material conversion process, which significantly influences chemical and phase compositions of the bio-calcium and hydroxyapatite powder derived from salmon bone waste.

Physical and chemical characteristics of Asian sea bass bio‐calcium powders as affected by ultrasonication treatment and drying method

“…The solubility values obtained in this work are similar to those of bio-calcium powders derived from salmon, skipjack, yellowfin tuna frame (7.65-10.8%) which were also digested using simulated gastrointestinal tract fluids (Benjakul, Mad-Ali, Senphan, et al, 2017;Benjakul, Mad-Ali, & Sookchoo, 2017;Idowu et al, 2020).…”

“…Ash, calcium, and phosphorus contents of all samples were 85.68%-86.36%, 33.43%-33.72%, and 19.82%-20.21%, respectively. The values are higher than those documented for bio-calcium powder from silver carp (Yin et al, 2016), skipjack tuna (Benjakul, Mad-Ali, Senphan, et al, 2017), and salmon (Idowu et al, 2020). Calcium and phosphorus molar ratios (Ca/P mole ratio) of the Asian sea bass bio-calcium powder (1.29-1.31) are lower than that 1.67 for pure Hap.…”

“…However, previous works have showed that the protein content of fishbone bio-calcium powder varied, depending on pre-treatment and fish species. For example, fishbone bio-calcium powder prepared by autoclaving pre-treatment of Asian sea bass bone showed lower protein content than those from skipjack tuna (Benjakul, Mad-Ali, Senphan, et al, 2017), salmon (Idowu et al, 2020), tonggol, and yellowfin tuna bones (Benjakul, Mad-Ali, & Sookchoo, 2017) prepared by alkaline pretreatment.…”

“…. Previous works have reported that fishbone bio-calcium powder contains 26%-30% of calcium content (Benjakul, Mad-Ali, & Sookchoo, 2017;Benjakul, Mad-Ali, Shenphan, & Sookchoo, 2017;Idowu et al, 2020). This fishbone powder can be used to fortify several foods to increase, not only calcium content but also the level of other minerals such as phosphorous, iron, magnesium, etc.…”

“…A previous study showed that fishbone bio-calcium powder had a mean particle size in the range of 10-30 µm (Benjakul et al, 2017;Benjakul, Mad-Ali, & Sookchoo, 2017;Idowu et al, 2020), which may not be well tolerated in food products. Therefore, reduced particle sizes are needed to facilitate the use of bio-calcium powder for food product fortification.…”