Herbs To Increase Milk Production Articles & Resources

Scientific evidence also suggests that milk and the components of milk may provide an ideal delivery system for other nutrients and health benefits (., immune function, intestinal health, blood pressure regulation, etc.). And recent heightened awareness of potential negative health implications of excessive consumption of soda are spurring beverage manufacturers to launch more healthful beverages in response to critics' claims that they are marketing empty calories to children.

Some of the most sucessful beverages introduced in recent years feature milk blended with coffee, tea, chocolate, fruit puree and juice. Take your grocery cart through the nutrition aisle and you will see six packs of meal replacement dairy-based beverages. Go into the canned and bottled juice aisle and you will find dairy-based smoothies and other dairy and fruit beverage combinations. Then go over to the coffee section or the Starbuck's kiosk in grocery stores and find milk with coffee (.a. Frappuccino) to perk you up. These are some examples of beverage marketers' attempts to capitalize on the growing interest of consumers in more healthful, good-tasting and convenient beverages.

Some of these non-traditional dairy-based beverages are sold in the dairy case as conventionally pasteurized products. However, more likely, they are sold beyond the dairy case.

What's increasingly common are extended shelflife (ESL) products (30-60 days refrigerated shelflife) or shelf-stable beverages (ultra high temperature [UHT] or sterilized/aseptic products with up to one year unrefrigerated sbelflife). These drinks are being merchandised throughout the grocery store, in vending machines, on the shelves of convenience stores and just about anywhere you can find a Coke or Pepsi.

Formulation beyond kitchen chemistry

Dairy-based beverages that maintain their quality for extended periods can create new channels of distribution and marketing, while providing added convenience for consumers. But they present unique challenges to the product and process development scientist. While one day in the kitchen with a good culinary chef may very well result in a great-tasting recipe, replicating it is another issue. Establishing a food or dairy beverage formulation that can withstand processing and storage and maintain the target product attributes in an economical way day-in and day-out requires skillful product and process development scientists and technologists working with chemists, microbiologists and engineers.

There are several questions that need to be answered when formulating blended dairy beverages. First, what are the nutrition goals with regards to calories, fat, protein and other nutrients? Since milk or a dairy ingredient may be one of the main ingredients in the formulation, a target protein level should be identified. Also, will the dairy protein be the full complement of milk proteins, one class of milk proteins (., caseins vs. whey proteins) or one particular milk protein (., [alpha]-lactalbumin, lactoferrin, etc. A decision must be made about adding other ingredients (., vitamins and minerals, fiber, herbs, inulin, etc.) that support any health message regarding the product. Such additional ingredients can influence the stability of the dairy components and may also impact the overall sensory quality of the product.

Beyond health considerations, there are other formulation questions. Will there be other ingredients such as coffee, cocoa or flavors added to the beverage? What is the desired color, clarity and acidity of the finished product? Will the intensity and flavor profiles of these ingredients remain stable in the proposed process and storage environment?

What you need to know

Because of the complexity of the formulation, and because many of these beverages undergo some thermal process to maintain quality for an extended shelflife, some inherent product instability issues must be addressed. Physical instability can manifest itself as sedimentation, phase separation (layers), undesired viscosity increases, chalky mouthfeel, creaming and gelation. Oxidation, browning, nutrient degradation and off-flavor development from poor microbial or chemical stability can also occur.

Knowing when such issues might arise, quantitatively measuring the change and devising effective solutions to remedy the situation are what make or break a dairy-based beverage. Some formulations require stabilizer systems, buffers, chelating agents and emulsifiers. In other cases, modification, or careful selection of ingredients and processes can overcome or minimize such issues.

There are two key processing steps common to many dairy-based beverages that must be properly addressed. These are heating (thermal processing) and exposure to acidic environments.

The acidic enviroment of a dairy-fruit type drink or carbonated dairy beverage, can affect the stability of some milk proteins. In particular, milk caseins become increasingly unstable as the pH is reduced from the milk pH of to, or below pH , which is casein's isoelectric point. This is where there is zero net charge on the milk protein and thus no net repulsion between protein particles and rapid precipitation/aggregation of large particles of casein. Protein-based emulsions can also become unstable. In some cases, pre-aggregated milk proteins (., yogurt powder) can be formulated with the appropriate stabilizers to maintain a dispersion of fine milk protein aggregates and produce an acceptable beverage. In other cases, selection of other milk proteins (., whey proteins such as [alpha]-lactalbumin instead of caseins) can be used more successfully to produce acidic dairy-based beverages with high clarity.

The manufacture of almost all milk and dairy-based beverages involves some type of heat treatment. The main objective of the heat treatment is to kill microorganisms and inactivate enzymes to improve the products' keeping quality and to make the products safe for human consumption. Heat treatments can produce physical and chemical changes in beverages. Standard pasteurization results in minimal changes, but more intensive heat treatments, such as UHT (ultra high temperature) processing, can lead to more significant changes such as: 1) a decrease in pH, which is associated with production of organic acids, degradation of lactose, loss of carbon dioxide and changes in the state of calcium from the ionic to colloidal forms. This reduces casein stability and accelerates other undesirable chemical reactions; 2) denaturation of serum proteins and creation of reactive thiol groups, which increases viscosity, affects protein solubility and causes release of [.2]S (cooked flavor); 3) an increased rate of reaction between protein and lactose, which accelerates Maillard browning reactions; 4) aggregation of caseins, which causes an increase in viscosity and changes in perceived mouthfeel (sometimes chalkiness) of the beverage; and 5) creation of environments that allow heat-stable, residual sporeforming bacteria to germinate, grow and cause proteolysis and lipolysis.

Some approaches have successfully obviated the potentially negative changes that can occur during heat processing. Careful selection of ingredients reduces the incidence of heat-stable spores surviving in the finished dairy beverage. Use of select phosphates and citrates reduces available ionic calcium, and use of pectin, carrageenan or other polysaccharides helps control protein aggregation. In addition, selection of dairy ingredients (processed for high-heat stability) may also improve the overall quality of thermally processed dairy-based beverages.

This article was written by Phillip Tong, professor, and Carolyn Podgurski, senior research associate, both with the Dairy Products Technology Center at California Polytechnic State University, San Luis Obispo, Calif.