By Rachel Zemser, CCS, Contributing Editor

It used to be an easy choiceyou could buy your tomato sauce smooth or chunky and that was about it. But those simple saucy selection days are over, and now the dizzying number of sauces are not only in the pasta aisle, but in the ethnic section of the supermarket, as well. With every sauce from Chinese barbecue to tamarind paste, a consumer can now easily and conveniently recreate almost any dishno matter its country of originvia a ready-to-pour, heat and eat sauce or condiment. 

Sauce versus condiment

The words "sauce" and "condiment" are often used interchangeably to describe a flavorful liquid or paste-type ingredient that is added to vegetables or protein to make it more flavorful and/or more unique, but there are characteristics that differentiate the two. A condiment is typically used to describe a thick, intensely flavored sauce or paste that can be used to accent a dish or as a dipping sauce. A  sauce is usually thinner and more mild-tasting,- and is a major part of the dish itself. For example, ketchup is a condiment; tomato sauce is a sauce. From a technical formulation standpoint, a condiment typically has higher salt, higher sugar and an overall lower water activity. Because of this, condiments have a much longer shelf life and can be processed at lower temperatures, or even cold-filled if the pH is low enough and preservatives are added. Luckily, the very barriers that inhibit microorganisms also give these products unique flavor and texture. Highly concentrated salts, sugars and spices found in condiments play a dual role of both flavor and function. On the other hand, simmer sauces and marinara typically contain more water  and are not quite as intensely seasoned. The higher amount of water and resulting thinner product make sauces more susceptible to bacteria growth; thus, they must be processed via high-heat pasteurization or retort.

Classic sauces

The classic and most common sauces on the market, the benchmarked ones with the most variation, are barbecue, marinara and salsa. Go to any supermarket aisle and count the variety of flavors and quality available. There are high-end sauces in the $5 to $13 dollar range, and economy varieties that cost between $1 and $3 per jar. Consumers often wrongfully assume these products have a lot of preservatives and unclean" labels, but actually, most of the mainstream tomato-based sauces on the market are thermally processed, at high-enough temperatures to keep unopened product shelf stable, eliminating the need for microbial inhibitors. Food scientists also continuously strive to clean up labels by using unmodified food starches, natural flavors and sweeteners like sugar, honey and agave versus the less-consumer-friendly high-fructose corn syrup.  Even if calories and carbohydrates stay the same, a sauce manufacturer can still highlight the made with natural ingredients" portion of their label. The latest Paleo diet trend calls for even lower sugar, minimal carbs and clean vegetable or protein ingredients. This trend will probably lead to more of the classics with less of any type of sweetenereven the natural options.

Ethnic sauces

As consumers become more educated about ethnic foods, they are demanding more variety in the sauce aisle. Both the sauce aisle and the ethnic sections of the supermarket are becoming larger as chutneys, curry, and hoisin all fight for shelf space with moles, chimichurris and Chinese barbecue sauces. These ethnic items used to be hard-to-find imports, but now U.S. co-packers are making their own lines of upscale ethnic sauces that have cleaner labels and modern artwork designed to entice even the most unadventurous consumer to try new flavors. Ingredient companies have responded to manufacturers' need for ethnic and flavorful ingredients. We have a line of all-natural herb and oil blends that can be infused into any sauce, condiment or marinade. We also do customized herbal blends per the manufacturer's special ethnic requests," says Scott Adair, executive chef, Supherb Farms, Turlock, CA. The company offers a range of ethnic flavors, including Jamaican jerk, Latin sofrito, ancho lime, Moroccan harissa, and Thai red and green curry. "These ethnic sauces may hail from other places, but the food safety rules are the same, and the right processing conditions must be used to create shelf-stable product," he says. "Their processing condition depends on the ingredients, the water activity, the viscosity and whether it is going to be a shelf-stable or refrigerated product.

Processing options

Sauce or sauce components" can be produced in several ways. The most flavorful way is to use minimal thermal processing and market it either as a short-shelf-life refrigerated item or as a frozen hockey puck" in a meal kit (the sauce puck melts when the product mixture is heated in the microwave or on the stovetop). These limited-shelf-life methods produce the best-tasting sauces, but they are also the most expensive. Shelf-stable jarred sauces and condiments are thermally processed to sterility and are the least expensive way to produce sauces with optimal quality and nearly eternal shelf life. Unfortunately, this method utilizes high-heat thermal processing, which can affect the finished product quality.

"Some typical issues that sauce manufacturers may experience can include separation -- stemming from either low viscosity and/or emulsion instabilityand textural changes, such as graininess, gelling, and/or watering off (syneresis)which may arise predominantly during freeze/thaw cycling, but can also be experienced during refrigerated storage or at ambient temperatures, in the case of shelf-stable products," notes Joe Eisley, Project Leader, Customer Solutions and Product Innovation, Ingredion, Inc., Westchester, IL.

Refrigerated sauces

 Refrigerated sauces are made very similarly to the way a consumer would make a sauce or condiment at home. For these, the ingredients are mixed together in a clean, FDA-approved manufacturing plant. These fresh sauces, typically tomato-based, have a pH below 4.6 and no preservatives. The resulting sauce or salsa have an approximately 30-day shelf life. The low pH and refrigerated temperatures prevent pathogen growth, but a preservative system would be needed to extend the quality and inhibit the yeast and mold. One important factor that can extend the shelf life of a refrigerated sauce is the manufacturing facility sanitation procedures. A plant needs to ensure that all ingredients and processes are kept cold and clean throughout the entire process. If Good Manufacturing Procedures (GMPs) are in place and followed consistently, a company can reduce or eliminate the need for preservatives and extend a product's shelf life by simply keeping the bacteria out via proper sanitation and refrigeration.

Frozen pucks

Consumers love the convenience of a meal kit that includes a vegetable, meat and sauce component. Instead of packaging the sauce separately, product developers can flash-freeze the sauce into a puck shape or smaller chunks so the sauce can be tossed right into the bag with the other components. These sauce pucks present some challenges. Creating a stable puck that wont separate involves using some hydrocolloids to keep the sauce intact as it works its way from manufacturing plant to consumer microwave.

Syneresis occurs when native starch retrogrades after heating and the starch molecules reassociate, which 'squeezes' out the water," says Steven Smith, principal scientist, Penford Food Ingredients, Centennial, CO. "Using a freeze/thaw starch, like a waxy corn or a tapioca-based  starch, prevents that re-association and allows the starch to hold onto the water."

Jane Kuc, senior research and development scientist, Gum Technology Corp., Tucson, AZ, adds: Hydrocolloids can bind and organize water, which can help prevent syneresis. Syneresis is a common issue with sauces that are frozen. Hydrocolloids such as locust bean gum or a combination of citrus fiber, xanthan gum and gum arabic are great options to prevent purge and provide freeze/thaw stability."

Thermally processed sauces

Refrigerated and frozen sauces taste great and command a premium price, but for most consumers and the foodservice industry, shelf-stable sauces are the most cost- and space-efficient way to go. There are several ways to create shelf-stable sauces, and the packaging methods vary, as well. The general categories of shelf-stable sauces include low-acid, retorted sauces, high-acid and pasteurized, acidified/pasteurized, and aseptic (in the box). All four methods rely on a combination of heat and acid to make the sauce or condiment commercially sterile. A general rule of thumb is, the higher the acid, the lower the heat needed, so foods with no acid must be subjected to retort temperatures (about 250°F), whereas higher-acid food can be cooked in the 195°F range. Harsh processing conditions can affect the sensory characteristics of a sauce, and low-fat or fat-free products are susceptible to compromised sensory qualities," says Ibrahim Abbas, Ph.D., senior R&D manager, Penford Food Ingredients. Glossy and smooth appearance is one of the key aesthetic attributes of sauces, and using a modified rich starch can help maintain that glossy and smooth appearance by mimicking the rich mouthfeel of a full-fat product."

Low-acid sauces

Low-acid (LAC) foods have a pH greater than or equal to 4.6 and a water activity level above 0.85, and are packaged in sealed containers that create an anaerobic environment. This is an important category because pathogenic bacteria grow well at pH ranges above 4.6, especially Clostridium botulinum, an anaerobe that produces a deadly toxic spore inside the can. LAC foods must be thermally processed in a retort to inactivate the bacteria and the spores. LAC foods" used to refer only to canned foods; however, low-acid packaging technology now also includes flexible and retortable (250°F) pouches, as well as glass jars of creamy, dairy-based sauces, like Alfredo sauce. LAC foods must be made in a dedicated processing facility regulated by FDA or USDA, and in California, these products are also subject to state regulations. A processing authority"defined  in Chapter 21 of the Code of Federal Regulations, Section 113, Part 83as a "qualified person having expert knowledge of thermal processing requirements for low-acid foods in hermetically sealed containers and having adequate facilities for making such determinations"must validate LAC thermal process times and temperature schedules. An LAC food should be developed with the assistance of an LAC facility R&D center. The R&D center will use a processing authority to determine the critical processing parameters that ensure the products safety. The effects of the retort on quality can be drastic, so food product designers may want to compensate for loss of flavor and texture by adding additional ingredients before the product is cooked. 

For example, Most of your dried herbs have between 8% to 10% of the oils left, and once you retort or pasteurize these herbs in a sauce, they loose all their flavor," says Scott Adair, corporate executive chef, Supherb Farms. "Supherb Farms freezes their herbs hours after harvest, which locks in all the volatile oilsthose flavors will come through stronger in a finished, thermally processed sauce."

Stabilizer systems should also be considered in products going through a retort, says Kuc. High heat can take a toll on many common components within a sauce," she says. "Finding hydrocolloids that hold up well in high-heat systems helps to prevent breakage in the sauce. Another consideration to keep in mind when utilizing a high-heat process is the target viscosity when hot. Xanthan gum is very stable in high-heat systems and will maintain its viscosity throughout the process. We have seen great success when combining starches with xanthan, guar and gum arabic in a high-heat sauce application, and this combination also works well in sauces that will subsequently be held on a steam table and subjected to further thermal breakdown."

High-heat applications typically require using a more process tolerant starch, especially when at low pH and/or undergoing some degree of shear, according to Eisley. "In general, modified starches that are on the more chemically cross-linked side of the spectrum are chosen for low-pH applications," he says. "If the application is at more neutral pH, or contains a high level of fat, and/or does not employ much shear, a moderately cross-linked modified starch can be chosen. Starches that function as fill viscosifiers are designed to aid in filling of cans or jars, ensuring even distribution of garnishes, and then break down during retort processing."

Acidified sauces

 The official FDA definition of an acidified food (AF) is a low-acid food to which acid or acid foods are added, that has a finished equilibrium pH of 4.6 or below, and that has a water activity level greater than 0.85. Multiple regulations govern how to formulate or process an AF food to make it shelf stable, but here are the basics: if enough acid or acid ingredients (e.g., citric acid, vinegar, lemon juice and other acidic fruits) are added to a low-acid food (e.g., bananas, meat and beans), the blend may yield a final equilibrium pH below 4.6the pH you want to fall below to help make your product shelf stable. The process of forcefully acidifying" the product to get to this low pH level is what makes it an acidified food. If only a small amount of a low-acid food (say, less than 10% of the final product) is combined with a large amount of acid food, the product may be considered an acid food rather than an acidified food. A processing authority must make the final decision about whether a product is acidified and what the scheduled thermal process (heat treatment for the food) must be. All acidified foods are regulated because the pH 4.6 is the limiting factor for growth of Clostridium botulinum, which produces the deadly toxin that causes botulism.

What about the water activity (aw) part of this definition? A product with an aw below 0.85 does not support the growth of pathogens. If the aw is at or above 0.85, the product can support the growth of Clostridium botulinum. So, a product with an aw below 0.85 does not fall under the AF category. Examples of AF products include: fruit- and vegetable-blended baby food products; shelf-stable fruit and vegetable smoothies; tomato salsas with chunks of corn and vegetables; sauces that have more than 10% ground nut meal; pickles that have been acidified with vinegar (not bacterially fermented); banana purées that have been pre-acidified with citric acid and are being repackaged; very ripe mangos with a pH above 4.6; and oil and garlic condiments. Acidified foods do not have to be retorted like LAC foods. Once the pH is below 4.6, Clostridium botulinum cannot grow, so a 250°F cook temperature is not necessary. Officially, an acidified food has a pH less than 4.6. However, you should add enough acid to achieve a pH of about 4.2. Until the product equilibrateswhich might take hours or daysthe pH can fluctuate if the acid and low-acid ingredients are not well blended, or if the product contains large chunks of ingredients, particularly low-acid ones like corn or carrot pieces. A lower pH gives a safety window that allows for that fluctuation. Some manufacturers insist on a pH of 3.9 to ensure that the final equilibrated pH will not exceed the maximum that was submitted to FDA. Unfortunately, this can sometimes negatively affect the final flavor of a product, so be sure to do sensory testing to get the taste balance right. The pasteurization process and pH requirements may affect the final flavors and textures. Its important to keep in mind during the R&D process that certain hydrocolloids are more pH-tolerant then others says Kuc. If the system contains dairy or whey proteins, pectin is usually used to prevent degradation. The pectin, which has a negative charge, will form a layer around the positively charged protein. This will stabilize the proteins by repulsion interaction and keep them from degrading as well as protect them in a low pH environment." Using the right starch can help maintain texture in low-pH thermally processed sauces. Low-pH or high-acid systems combined with the presence of a high-heat thermal treatment causes the starch viscosity to breakdown, resulting in a thin and stringy texture in the fnished product, says Sarah Wood, Ph.D., senior applications scientist, Penford Food Ingredients. "Using a modified corn starch can help maintain viscosity in low-pH conditions."

Under pressure

One of the most popular new nonthermal processing technologies is high-pressure processing (HPP). Products produced via HPP are not heated; they can last for 30 days (refrigerated) and have a fresher uncooked taste. Right now, the market of HPP products is small and mostly consists of beverages; however, some salsas and guacamole dip have been made via HPP which has a fresh taste, minimal or no preservatives and a 30-plus day shelf life. They carry a hefty price tag, but some people think fresh, uncooked flavor is worth the cost. The process is also known as pascalization" in honor of the 17th-century French scientist Blaise Pascal, famous for research on how pressure affects liquids. HPP involves applying 100 to 1,000 megapascals (MPAs) of hydrostatic pressure to food products via a water bath. The water bath distributes the pressure equally, allowing the products to withstand the pressure without being crushed. The applied pressure essentially disables pathogens, yeast and molds to a safe level that can be maintained at refrigerated temperatures for up to 30 days. FDA, USDA and some European agencies recognize HPP as an effective lethal" process that significantly reduces microorganisms in food in the same way that pasteurization reduces the microbial load. The inhibition delays spoilage and increases shelf life, too. HPP products are fresh-tasting and do not have that cooked fruit" flavor characteristic of most thermally processed equivalents. For food scientists and product developers, HPP processing means using fewer preservatives and, thus, generating cleaner labels. The con is that HPP products are expensive to manufacture. A 12 ounce bottle of HPP juice can cost as much as $10 . As more companies use HPP, the price is likely to become more affordable. Some experts debate whether HPP has an effect on the live enzymes" that are part of the raw" appeal of ingredients like juices, arguing that the high pressure that inactivates the bacteria may also inactivate some of the enzymes.

Adding in ingredients

The processing conditions needed to create a shelf-stable sauce are strict and heavily regulated by FDA. The harsh processing conditions often result in flavor loss. Food scientists must take advantage of concentrated flavors that wont disappear during the thermal process. While dried herbs and spices or oleoresin can produce an acceptable flavor individually quick frozen (IQF) herbs, although more expensive, retain more of their oils and result in better-tasting product.

IQF herbs are used more often in shelf-stable sauces with higher price points. However, for a more economical sauce, sometimes a less expensive dried herb can be used in conjunction with natural flavors. This provides visual particulates and intense flavor at a lower cost. Some companies, like Kalsec, Inc., Kalamazoo, MI, have concentrated herbal oils and extracts that are soluble in either water- or oil-based mediums, allowing for use in both tomato-based sauces and salad dressings. Concentrated herb extracts can be plated onto salt and incorporated into spice blends as a way to minimize the number of ingredients needed, and reduce the cost of the overall spice blend by boosting the flavor and reducing the amount of actual herbs. 

Hydrocolloids, both gums and starches, are important for generating mouthfeel in the final product. Different hydrocolloids will affect the viscosity, rheology and cling of a sauce" says Kuc. Lambda carrageenan and tara gum are great options for adding cling and body to a sauce. They will add some viscosity and will provide a creamy texture."

Starches on their own can provide viscosity, but specialty starches can maximize the effect. "Specialty starches described as 'co-texturizers' that can also enhance properties such as cling and mouthfeel when used either alone or, as the name suggests, in combination with a standard viscosifying starch," says Angelina De Castro, marketing manager, savory, Ingredion. "By themselves, these co-texturizers do not provide much viscosity, but when used 'on top' of a standard thickening starch, they can greatly affect properties such as cling, mouthfeel and creaminessessentially altering the eating experience."

Processing considerations

Make sure you know the process rules when testing out novel ingredients like frozen herbs, IQF vegetables and hydrocolloids. They may need to be incorporated into the system in a way that ensures they will be well blended.

For example, Kuc explains, Since gums are hydrophilic, they react very quickly with water and, if the gum particles are too close to one another, they can stick together or clump. Depending on the ingredients in the system, there are a few different dispersion techniques that prevent lumps or fish eyes. A very effective method would be dry-blending the gums with other dry ingredients in the system. If the system contains oil or high Brix liquid, such as corn syrup, another option would be to add the gums to a small portion of this material to create a slurry. Since the gums are insoluble in these mediums, they will coat gum particles, which allows them to be dispersed before they begin hydrating. High sheer mixing is always helpful, as well."

Similar recommendations apply when making a starch-based sauce. Generally, pregelatinized starches will require moderate to high shear to uniformly and quickly disperse the starch" says Abbas. Preblending is a technique where starch is mixed with other dry ingredients, such as sugar, salt or seasoning, to help prevent fish-eye clumps of unhydrated starch. This dry mixture is added to the water to make slurry using a mixer. Cook-up starches are easily dispersed in water and cooked out without issues. One has to be careful when a starch has to be added to very hot water as this will gelatinize the surface of the granules." This can  prevent full gelatinization and cause clumping.

The same regulatory and technical rules that are used to make classic sauces, like marinara and salsa, can just as easily be applied toward the formulation of ethnic sauces, like chimichurri, mole and chunky chutney. Flavor and seasoning companies all have shortcuts to help you achieve global flavors without having to import special ingredients. While there will always be limitations on final quality and flavor, ingredient technology is constantly improving and seeking out ways to get the most authentic flavor at minimal cost.

Rachel Zemser, CCS, is a food industry consultant who has one foot planted in the artisan soils of San Francisco and the other buried deep in the world of R&D, manufacturing and food science. She has a B.S. and M.S. in food science, a culinary arts degree, and 18 years of food-industry experience. Zemser writes The Intrepid Culinologist blog on foodproductdesign.com and is a member of the Research Chefs Association. For more information, visit the intrepidculinologist.com.