[PROCESSING] by Tara McHugh

How Plant-Based Milks Are Processed

his month’s Processing column includes other ingredients like ses- worth $16.3 billion this year, up from continues the theme of “How is it ame seeds, rice, barley, cashews, $7.4 billion in 2010. Tprocessed?” with a focus on and tiger nuts. Unique horchata reci- In the United States, plant-based plant-based milk alternatives—their pes have been used as far back as milk makes up 9.3% of the total milk history, market, and nutritional ben- the eighth century to create this tra- market. Sales of refrigerated almond efits. Both common (almond, soy, ditional Spanish plant-based and coconut milk grew 9.8% and coconut, and rice) nondairy milk beverage. Rice milk is thought to 5.2%, respectively, this year, and alternatives as well as less common have been discovered more recently, sales of shelf-stable almond milk and (peanut, pea, oat, and other) non- in 1921 in San Francisco. coconut milk grew 4% and 3.3%, dairy milk alternatives are described, According to Nielsen data, retail respectively. The most popular plant- as well as their manufacturing steps sales of plant-based foods in the based milks are almond milk, coconut and quality control. United States rose 20% to $3.3 billion milk, rice milk, and soy milk. In 2010 in the past year, growing from a rela- almond milk surpassed soy milk in History, Market, and Nutrition tively niche market to a mainstream terms of popularity in the United Plant-based milks have a long history food category, with nondairy milks States. In Europe, soy and oat milks in many cultures around the world. representing the largest portion of are very popular. The strongest Almond milk has surpassed soy milk as the most popular The word “milk” has been used since the market at $1.6 billion. The global growth in the category this past year plant-based milk. Photo courtesy around 1200 AD to refer to plant plant milk market is estimated to be came from other plant-based milks, of Pexels juices. Of all the plant-based milks, coconut milk has the longest tradition of use. It originated in India and Southeast Asia and has been used as both a drink and an ingredient for nutrition and ceremonial offerings. Soy milk also has a long history and was discovered in 1365 in China. Traditionally, it was used in Chinese cooking. Later it was consumed as a drink, beginning around 1866. In 1910 the first soy milk factory was estab- lished near Paris and around the same time, the first soy milk patent was granted. More recently, in the 1970s and 1980s, soy milk has become increasing popular through- out the world. Similarly, almond milk is believed to have originated in the 13th century when it was first referenced in Baghdadi and Egyptian cookbooks, as well as in the English literature. Recently, in the 19th and early 20th centuries, the popularity of almond milk has soared. Horchata is a blended almond-based milk that

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which include milk made from peas, a large impact on the properties of the placed in large stainless steel kettles lupine, flax, hazelnut, cashews, and hemp. final beverages. A wide range of cereals, containing filtered water and a small The market increases in plant-based legumes, nuts, and seeds can be used to amount of salt. Soaking times vary based milks are in part driven by nutritional dif- make plant-based milks. The terroir and on the plant hydration rate but can take ferences between these up to 12 hours. Soaking and dairy milks. Plant- Soy milks are known for their protein contents, as are pea can remove enzyme inhib- based milks do not protein milks, which also are believed to have less impact itors, improving nutrient contain lactose or choles- digestibility and bioavail- terol, and many contain environmentally than some of the other plant-based milks. ability. It also softens the added calcium and B vita- plant to aid in further pro- mins. They are known for their high growing environment are important con- cessing. After soaking, the cereals, protein contents in comparison with tributors to properties of the plant-based legumes, nuts, or seeds are rinsed and other beverages. Soy milks are known for milk. Changes in climate, soil, and sur- drained. Next, they are ground into a their protein contents, as are pea protein rounding vegetation subtly change the smooth puree or paste. Hammer mills are milks, which also are believed to have plants and need to be defined to create commonly used at this stage in less impact environmentally than some of optimal final products. Following harvest- processing. the other plant-based milks. Rice milk is ing, conditions for storage prior to In some cases, enzymes may be popular among consumers who have processing are crucial to ensuring that added at this step or the soaking step to allergies to other plant-based milks, and the cereals, legumes, nuts, and seeds do hydrolyze starches, for example, for oat oat and some other plant-based milks not oxidize or degrade in quality before milk. In other cases, a blanching step may contain soluble fiber as an additional being processed into milks. be employed with or without the addition nutrient. • Wet Versus Dry Processing. There of sodium bicarbonate, as is performed for soy milks. Some nuts, like macada- mias, cashews, and pecans, grind easily, yielding smooth purees or pastes; how- ever, other nuts and plant materials, like almonds, retain undesirable textures after grinding due to their skins or other fibrous components. These fibrous com- ponents can be centrifuged or filtered out of the milks to obtain smooth final tex- tures. Alternately, fine grinding processes that result in very small parti- cle sizes can be used to obtain desired final consistencies. Heating and homog- enization are often performed at this stage to inactivate enzymes and improve stability of the final beverage. The second alternative process, the dry process, involves harvesting the plant, legumes or peanuts, for example, drying them (with or without blanching), and milling them into flours. Hammer, pin, or other types of mills may be used. The flour can then be processed to separate the protein from the starch and fiber as desired. Then the protein concentrate or isolate can be used in the next step to A technician measures the properties of Ripple pea milk. Photo courtesy of Ripple Foods formulate the beverage. The dry process often results in higher protein contents in A Look at the Processes are two main process methods for pro- the end products. What follows is a step-by-step look at the ducing plant-based milks. One is a wet • Formulating Into Beverages. During processes involved in producing a plant- process, and the other is a dry process. final formulation, water, flavors, vitamins, based milk. The wet process, which involves and minerals may be added. Nutrient lev- • Plant Growth and Harvesting. soaking and grinding, begins with the els and amounts of added sugar are Growing and harvesting conditions have cereals, legumes, nuts, or seeds being adjusted depending on the beverage. »» pg 64 12.18 • www.ift.org [PROCESSING]

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the future. Finally, it is envisioned that The market increases in plant-based milks are in part driven by nutritional advanced nonthermal technologies will differences between these and dairy milks. Plant-based milks do not contain be applied to plant-based milks commer- cially more often in the years to come. So lactose or cholesterol, and many contain added calcium and B vitamins. the next time you sip a plant-based milk, I hope you take pride and pleasure in Amounts of fat can also be modified, and and digestibility, nutrient and flavor anal- knowing some of what went into pro- thickeners and/or stabilizers added as yses, microbiological tests, and detailed cessing it. FT desired. In some cases, the pH of the sensory evaluations. slurry is neutralized by adding sodium • Packaging. After the plant milk is hydroxide. Final homogenization and heat processed, it is then packaged as needed treatment is completed prior to packag- for distribution and storage. Tara McHugh, PhD, Contributing Editor ing. Thermal processing is commonly • Research Leader, USDA Agricultural Research Service, Albany, Calif. used to ensure safety of the final plant- Recent Innovations • [email protected] based milks. High pressure processing Several innovation fronts are being can also be used. explored for plant-based milks. One of • Quality Control. Final product prop- these is the opportunity for plant-based erties are monitored during development milk blends. Blends such as almond/oat REFERENCE of plant-based beverages, as well as dur- and almond/cold brew coffee are trendy Sethi, W., S. K. Tyagi, and R. K. Anurag. ing production, in order to ensure and increasing in popularity. The market 2016. “Plant-based milk alternatives an optimum final product quality. Some of and types of fermented plant-based bev- emerging segment of functional beverages: a review.” J. Food Sci and Tech. 53(9): the quality parameters tested include erages, although not discussed in this 3408–3423. viscosity, particle size, protein content column, are also anticipated to grow in

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