Plant-based milk alternatives are a rising trend worth today USD 23 billion and is expected to grow 12.5% annually until 2028.  The increasing consumption of plant-based milk alternatives coheres with growing ethical and environmental concerns.  Moreover, health conscious consumers might be attracted to plant-based milk alternatives due to cow milk allergy, lactose intolerance, calorie concerns or prevalence of hypercholesterolemia.  Also in countries where mammal milk is scarce and expensive, plant milk substitutes serve as a more affordable option. 
However, dairy products contribute between 52% and 67% of the dietary reference intake of calcium to the American diet.  Thus, cow milk is a good source of calcium , a mineral that has many functions within our bodies. Only 1% of the calcium in the human body mediates a number of functions including blood clotting, nerve transmission, hormonal secretion, muscle function and blood vessel contraction. The remaining 99% of the calcium in the body is stored in bones and teeth where it provides strength and support for their structure. 
While cow‘s milk contains 120 mg per 100 mL calcium, the calcium content of unfortified milk alternatives derived from oat, almond and soy ranges from 0 mg to 30 mg per 100 mL in commercially available plant-based milk alternatives. [3, 8]
An ideal milk-alternative would provide comparable levels of calcium to assure the consumers to meet their nutritional requirements and to reduce the requirement of nutritional supplementation. Therefore, calcium fortification is generally adopted in preparation of plant-based milk substitutes. 
Calcium fortification with Jungbunzlauer
Jungbunzlauer’s tricalcium citrate has several desirable properties for calcium-fortification of plant-based milk-alternatives:
First, the organic tricalcium citrate shows superior bioavailability compared to inorganic calcium sources such as oxides, carbonates and phosphates, which is indicated in several scientific studies. [9,10]
Secondly, tricalcium citrate shows a solubility of 1.2 g/L at pH = 5 and room temperature. Therefore, it remains mainly dispersed instead of dissolved in the product matrix. This has the advantage of low impact on the taste and negligible impact on the product matrix itself since the effect on proteins and product pH is minimal – even at high concentrations and during heat treatment.
Moreover, tricalcium citrate is less soluble at higher temperatures and high pH, which is described as ”inverse solubility“. This is beneficial during heat treatment, as the risk of coagulation or syneresis and reactions with other ingredients of the product can be further reduced. 
Undesired side effects of tricalcium citrate being mainly dispersed in the product are possible grittiness and sedimentation in low viscous products. The grittiness can be avoided by applying ultrafine micronised tricalcium citrate (TCC M1098, finest available tricalcium citrate). The sedimentation speed depends on particle size and viscosity.
In our trials, smaller particle size of tricalcium citrate leads to a reduction of sedimentation speed compared with the coarser granulations. However, without stabiliser, even the ultrafine version of tricalcium citrate shows a sedimentation of 90% after 5 min. The more significant measure to avoid sedimentation is to increase the viscosity of the product.
No sedimentation was visible after 30 days of ultrafine tricalcium citrate in a concentration of 120 mg calcium in 100 mL demineralised water (milk calcium content) when stabilised with 0.035% TayaGel® HA (high acyl gellan gum).
In the next step, a recipe was developed for a calcium fortified oat drink. When producing oat milk, it is necessary to apply enzymes that break down the starch into glucose and isomaltose. Otherwise, the oat drink would show a porridge-like viscosity. Tricalcium citrate was added in the concentration of 120 mg calcium per 100 mL. For stabilisation, TayaGel® HA was added and in a last step, the oat drink was heated to 142°C (UHT, 287°F) in order to inactivate the enzymes and to ensure a long-shelf life. Different concentrations of TayaGel® HA were tested. The results indicate that depending on the recipe 0.025% to 0.035% TayaGel® HA would be suitable for stabilising tricalcium citrate over the shelf life. Depending on the particular recipe higher levels might be necessary. In our trials, no phase separation or sedimentation was visible after 65 days with a concentration of 0.025% TayaGel® HA.
One serving (8 fl oz) of 2% milkfat dairy milk contains 309 mg of calcium, 29.4 mg of magnesium, 390 mg of potassium and 1.05 mg of zinc, according to the Food Data Central, a database by the U.S. Department of Agriculture. 
The mineral content of unfortified oat milk and almond drinks were analysed and show a nutritional gap to dairy milk:
Table 1: Mineral content of unfortified oat and almond drink. The nutritional data are obtained by laboratory analysis and is the average of a two-sample measurement:
Therefore, mineral fortified oat and almond based milk alternative recipes were developed with the mineral profile of dairy milk. The final recipe for the mineral fortified oat drink contains 339 mg calcium, 468 mg potassium, 44 mg magnesium and 2.4 mg zinc per serving (240 ml). The final recipe for the mineral fortified almond drink contains a calcium content of 329 mg calcium per serving (240 ml), 41 mg magnesium, 477mg potassium and 2.2 mg zinc. Stabilised with 0.035% TayaGel® HA for the mineral fortified almond drink and 0.025% TayaGel® HA for the mineral fortified oat drink, even after 21 days, no sedimentation or phase separation was observed in the mineral fortified oat and almond drinks. You can find the recipes for the mineral fortified oat and almond drinks.
 Grandview Research. (Version: April 2021) Dairy Alternatives Market Size, Share & Trends Analysis Report By Source (Soy, Almond), By Product (Milk, Ice Cream), By Distribution Channel (Supermarket & Hypermarkets, Online Retail), And Segment Forecasts, 2021 – 2028. Retrieved December 21, 2021, from www.grandviewresearch.com/industry-analysis/dairy-alternatives-market
 Zhang, Y.Y., Hughes, J., Grafenauer, S. Got Mylk? The Emerging Role of Australian Plant-Based Milk Alternatives as A Cow’s Milk Substitute. Nutrients 12, 2020,1254.
 Sethi, S., Tyagi, S.K., Anurag, R.K. Plant-based milk alternatives an emerging segment of functional beverages: a review. J Food Sci Technol 53, 2016, 3408–3423.
 Mäkinen, O.E., Wanhalinna, V., Zannini, E., Arendt, E.K. Foods for special dietary needs: Non-dairy plant based milk substitutes and fermented dairy type products. Food. Sci. Nutr. 1, 2015, 1-21
 Rozenberg, S., Body, J. J., Bruyere, O., Bergmann, P., Brandi, M. L., Cooper, C., et al. Effects of dairy products consumption on health: Benefits and beliefs - a commentary from the belgian bone club and the european society for clinical and economic aspects of osteoporosis, osteoarthritis and musculoskeletal diseases. Calcified Tissue International 98, 2016, 1-17.
 Astolfi, M.L., Marconi, E., Protano, C., Canepari, S. Comparative elemental analysis of dairy milk and plant-based milk alternatives. Food Control 116, 2020, 107327.
 National Institutes of Health. (Version: November 17, 2021). Calcium e fact sheet for health professionals. Retrieved November 24, 2021, from ods.od.nih.gov/factsheets/Calcium-HealthProfessional/
 Chalupa-Krebzdak, S., Long, C.J., Bohrer, B.M. Nutrient density and nutritional value of milk and plant-based milk alternatives. International Dairy Journal 87, 2018, 84-92.
 van der Velde, R.Y. et al. Calcium and vitamin D supplementation: state of the art for daily practice. Food & nutrition research, 58, 2014.
 Vrese, M., Gerstner, G. Tricalcium citrate (TCC) and health. J Nutr Health Food Eng., 6(5), 2017, 130-146.
 Gerhart, M., Schottenheimer, M. Mineral fortification in dairy. Wellness Foods Europe May, 2013, 20-26.