Prepared Pasta and Rice Dishes - Part One

By Lynn A. Kuntz, Editor

Using the Noodle
Pick your Pasta
The Rice is Right
Flavor Appeal

What's typically easy to prepare, healthful, inexpensive and appeals to a wide variety of consumers? The answer lies in take-out establishments and throughout grocery shelves and freezers: prepared pasta and rice dishes. Convenience at the cash register requires a sizable amount of work in the lab to guarantee the finished product meets expectations.

Today's consumers want either packaged mixes they can cook and serve within minutes, or completely prepared products they can heat (or not), and eat on the spot. Though the concept is simple, the execution is anything but, due to the complex nature of the ingredients, processes and consumer requirements. Like the food pyramid, the base consists of grain-based products. And although pasta and rice alone are nutritious, as they say, variety - in the form of sauces and seasonings - is the spice of life.

Using the Noodle

A number of dough-based products fall under the category of pasta, including noodles, macaroni and various specialty items, such as ravioli, gnocchi, couscous and ramen noodles. The word "noodle" often is used generically, but FDA has reserved this term as well as the term "macaroni" for 15 different categories defined by standards of identity. These are in 21 CFR, Sections 139.110 to 139.180, and include macaroni products ("regular," enriched, enriched with protein, milk, enriched and nonenriched nonfat milk, enriched and nonenriched vegetable, whole wheat, and wheat and soy) and noodles ("regular," enriched, enriched and nonenriched vegetable, and wheat and soy).

The standards allow noodles and macaroni formulated with semolina, durum flour, farina or flour. Durum wheat, a hard spring wheat, makes the best pasta. Durum semolina, a granular form (150 to 450 microns) of flour from the endosperm, produces the highest-quality pasta. It contains optimum proportions of two amino acids (gliadin and glutenin), which are essential for proper gluten development and natural pigments (xanthophyll, carotenoids) to make the typical amber-yellow color of premium pasta. Semolina imparts resistance to overcooking, cuts starchiness, and lends a firm bite and characteristic flavor. The higher the flour's ash content, the softer the texture and the grayer the color. Unenriched pasta usually contains 12% to 14% protein.

Egg noodles usually contain durum flour, which has a smaller particle size than semolina. The standards require 5.5% egg solids (whole egg, yolk or a combination) on a dry basis. Yolk produces a deep yellow color; the white's protein improves cooking quality and gives a firmer bite. Macaroni consists of durum semolina and water, and any other ingredients listed in the standards. For instance, vegetable macaroni contains a minimum of 3% vegetable solids, but only tomato, spinach, beet and several others are allowed. Adding vegetables produces mainly color, little flavor and a loss in cooking quality.

For specialty markets or ethnic designs, certain pasta products contain rice, potato, buckwheat, quinoa, amaranth or other grains. Because of the lower protein content, the pasta is softer, loses more starch during cooking, and can be easily overcooked.

A typical dry packaged mix only requires cooking prior to serving, so standard pasta will suffice. However, pasta used for more severe applications, such as freezing, steam-table use or retorting, requires added strength. Long cook periods turn pasta starchy and unacceptably soft. Thick-walled pasta withstands severe conditions better than thinner shapes. For retort applications, most pasta goes uncooked into the can (this minimizes heat exposure). But this practice increases finished-product starchiness as the starch sloughs off during heating.

CFR also allows egg albumen, alginate and glyceryl monostearate in noodle and macaroni formulations to add process tolerance. The egg-white protein strengthens the network that holds the starch in place during cooking and gelatinization. Glyceryl monostearate complexes with amylose, forming insoluble helical structures that hold in the starch and decrease water absorption; this reduces starchiness and stickiness.

Although generally not included in macaroni and noodle standards, other ingredients may be added to pasta: fiber, herbs and spices, and other flavorings. Onion, celery, garlic and bay leaf are listed in the standards, though. Most additives, especially at high levels, can adversely affect the texture by reducing the protein level needed for a strong matrix. Also, hygroscopic ingredients can make drying to the target moisture difficult. Ingredients that provide visible particulates also can clog extruders.

Pasta is formed by extrusion, or sheeted and cut. Long goods - pasta such as spaghetti and lasagna - range from 10 to 20 in. or longer. Short goods are up to 3 in. long. Shapes such as bow ties require specialized equipment for cutting and bending.

Standard pasta is dried to approximately 12% moisture to ensure shelf stability. Some manufacturers use a traditional low-temperature process. Others dry at higher temperatures, which cuts the drying time, seems to improve the cooking quality and color, reduces the microbial load, inactivates flour enzymes, and increases its resistance to overcooking. The proper drying conditions depend on the pasta's geometry (shape, dimension, mass-to-surface ratio, etc.), with thinner products taking significantly less time to dry than thick-walled products. For refrigerated applications, pasta is dried to reduce moisture and may be steamed slightly before storing in gas-flushed packaging. The inert gas inhibits microbial growth, providing a shelf life of up to 12 weeks.

Precooked pasta is cooked in water near 988 to 998C, or it can be prepared with superheated steam and humidity kept at saturation levels. Immediate cooling halts further cooking prior to final refrigeration, packing or freezing. Sauces or seasonings can be added, and the product can be frozen in a tunnel or a spiral freezer with cryogenic gas or conventional cold air to -188C or lower.

When dry pasta is put into the same package as a seasoning mix, the pasta moisture can migrate to a hygroscopic seasoning, causing lumping or inducing other moisture-related problems. For this application, manufacturers typically specify a pasta moisture of 8% or less, depending on the application and mix formulation. Dried pasta can pick up moisture in humid conditions and lose moisture in dry conditions. Usually packaging without moisture barriers is preferred, since tight plastic liners, high humidity or heat can promote mold. The shelf life of pasta is up to two years - less under more humid conditions.

Improper drying can cause checking. The pasta surface case-hardens, trapping the moisture inside. Later, this moisture migrates to the surface, creating pressures that cause the pasta to crack. This can occur soon after drying, or much later, which will cause pasta to shatter when cooked.

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Pick your Pasta
The innumerable shapes and sizes of pasta make it difficult to decide what's best for a specific application. Several considerations influence the choice:
Labeling and product name. Several shapes are defined in the standard of identity: macaroni (tube- or cord-shaped with a diameter from 0.10 to 0.27 in.); spaghetti (tube- or cord-shaped with a diameter from 0.06 to 0.11 in.); vermicelli (cord-shaped, not tubular and with a diameter no more than 0.06 in.). Others are named for their traditional shapes: penne, rigatoni, orzo, farfalle (bow ties), radiatore (little radiators), etc. Italian pasta comes in more exotic shapes, such as spiral-shaped chiocciole or horn-shaped cornetti.
End use. The application greatly influences the shape and size used. Thicker-walled pasta needs an increased cook time, so it holds up better and is firmer. Delicate angel-hair pasta turns to mush in a retort or steam table, or if the consumer overshoots the cook time. A better option for code tolerance would be a thick-walled rigatoni. Plus, the traditional rigatoni shape can be modified to meet the rigors of handling, processing and packaging - it can be shrunk in size to facilitate a filling operation or lessen weight overruns.
Quick-cooking packaged mixes require instantized pasta, and several technologies have been developed. Instant pasta only requires boiling water for rehydration and would be used in an instant cup-type product. A ramen, or fried noodle, results in an oriental-style instant noodle. Another option is freeze-drying precooked noodles, but this is very expensive and not readily available in the United States. Another method uses steam to pregelatinize thin-walled pasta. This is then dried conventionally for a quick-cooking pasta (five to six minutes) or puffed, so it is instantized. This technique reduces cook tolerance.
Couscous, a type of instant pasta, is gaining popularity because of its use in Mediterranean cuisine. The small granules can be rehydrated with boiling water in three minutes to a fluffy, rice-like consistency. Like instant pasta, it requires a steaming step to pregelatinize the starch.
Gnocchi (potato dumplings) are formed from an extruded dough of precooked potato flour and/or potato flakes and soft wheat flour. Additional equipment can form surface ridges, and coat the gnocchi with rice flour to reduce sticking. They are typically manufactured as a refrigerated or frozen product, with a moisture content from 50% to 70%.
Filled pastas, such as ravioli and tortelleni, use the same dough ingredients as macaroni or egg noodles, but carry a wide variety of fillings, not just cheese or beef, but chicken and prosciutto or basil and walnuts. Ravioli dough is sheeted, the filling deposited and the dough is cut and sealed using stamping dies that produce single pieces or strips. Some equipment produces single dough sheets where the sheet is folded and pressed after the filling has been deposited. Others form double sheets, with the filling deposited on a bottom sheet, covered with the top sheet, then pressed, sealing the two sheets on the ravioli edges.
Tortellini is not stamped; forming machines fold a small pasta strip laterally over the filling, joining and sealing two opposite edges or pinching them. The classic tortellini shape is a ring, empty in the center, but the word "tortellini" also often refers to shapes without a space in the center such as capelletti. Tortellini are easily dried due to a small dimension and favorable weigh-to-surface ratio. Most filled pasta is left at higher moistures for a retorted, refrigerated or frozen product.

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The Rice is Right

Unlike pasta, rice only comes in one general shape - rice-shaped. But that doesn't mean that rice-based dishes need to be boring or that they don't require much thought to design. This month's Culinary Connection offers some insight into this grain's versatility. Thousands of rice varieties exist, but the three main types are categorized mainly on the basis of size and amylose content: long-grain, medium-grain and short-grain. When cooked, they yield different characteristics.

Long-grain rice. Highest in amylose (23% to 26%), long-grain cooks up dry and fluffy, with distinct grains three to four times longer than their width. Long-grain offers the best kernel integrity, and maintains uniform kernels after it is frozen and reheated. It retains moisture better than most other types of rice. Specific varieties have superior overcook and abuse resistance, and are recommended for canning applications. This variety also has the highest gelatinization temperature: 748C.

Medium-grain rice. The kernels are two to three times longer than their width. A higher amylopectin content (18% to 26%) makes cooked medium grain soft and tender, and cling together. Short-grain rice. A high amylopectin content and lower amylose content (15% to 20%), gives short-grain a tender, sticky, almost creamy texture.

Processing these rice varieties yields a wide range of characteristics that help determine which is best for a particular application. Most rice is milled, removing the outer bran. Brown rice retains the bran, giving it different characteristics from milled rice. In addition to the characteristic color and flavor, bran absorbs water at a slower rate than the starchy endosperm. This causes the bran layer to split irregularly so that the cooked grains look torn and misshapen. Slower water absorption also means that brown rice takes longer to cook than white rice, about 40 to 50 minutes as compared to 15 to 20 minutes for regular milled white rice. The unsaturated rice-bran oil is subject to rancidity, so brown rice has a shorter shelf life than milled white rice. Unmilled rice may first be steamed, creating parboiled rice. The heat gelatinizes the starch, which reduces breakage and creates firmer, more separate grains. Parboiled rice requires a longer cook time than regular milled white rice (about 25 minutes)and also can absorb more water.

Quick-cook applications, requiring a six-to-eight-minute cook, can use rice processed to expand the kernel structure without precooking. This speeds penetration of water, and helps maintain the kernel integrity and flavor. "It doesn't have that precooked flavor and texture," says Don McCaskill, director, R&D, Riceland Foods, Inc., Stuttgart, AR. "It is actually less sticky than the rice it is produced from." According to Dean Oliver, Riceland's pilot plant coordinator, long-grain and medium-grain versions are available. Specialty rices also have been tested, and while no short-grain quick-cook rice is on the market, he doesn't see any reason "why it wouldn't be technically feasible." But he notes that reduced stickiness "might not be an advantage in a short-grain application."

Instantized rice rapidly absorbs boiling water, making it ready for consumption in several minutes. The process opens up the kernel structure for rapid hydration by completely precooking, then drying. The texture is often less firm and the appearance differs from that of regular rice. Freeze-drying rice gives the kernel a much more open structure, so it can be rehydrated in minutes without boiling.

"Over the years, the rice industry has considered anything that is five minutes or less cook time as instant - that might be different from other ingredients where the word 'instant' refers to something that you just add hot or boiling water and let sit," says McCaskill. "Generally, a cup-of-soup-type product would require a freeze-dried rice, which is fully cooked, then freeze-dried, or an oven-puffed rice. The latter has a bit of a toasted flavor and browning, but that might not be a problem in some applications."

In addition to rice type, the cooking method affects the finished product. "Risotto usually calls for Italian arborio rice, noted for its creamy, sauce-like character," says McCaskill. "We can basically achieve the same thing using a medium-grain rice variety produced here by following the same cooking technique, adding part of the water at a time, and continuing to stir it while cooking." Covering and cooking rice results in a steamed effect, and might keep less starch from leaching out.

Refrigerated or frozen products might call for individually quick-frozen rice. This saves the capital cost of in-plant rice cook-up, and more importantly, provides a free-flowing product for the filling operation. Otherwise, preparation and hydration of the rice can be done on most types of blanching or cooking equipment, including steam-jacketed kettles or auger-driven continuous cookers.

Long-grain parboiled is the rice of choice for frozen applications, says McCaskill. If the in-house cooking equipment is marginal in terms of cook time, he suggests quick-cook as the next best option. "Typically, for products that require reheating, you would intentionally undercook the rice during manufacturing," he suggests. "You would probably target a 65% moisture on the rice." Normal, fully cooked rice is about 70% to 73% moisture.

After cooking, the rice requires cooling prior to mixing with sauce or seasoning ingredients. Otherwise, if the rice is above its gelatinization temperature, the kernels continue absorbing water, softening their texture and changing the sauce's characteristics. "The gelatinization temperature is about 708C for long-grain varieties, and usually a little lower for medium- and short-grained varieties," says Zack Nehus, research engineer at Riceland. "It would continue to absorb water until it turns to a paste. That's one of the problems seen in retorting rice."Quick-freezing after adding the sauce to the mixture gives the sauce minimal time to penetrate the rice. Also, rice held above the freezing point might give up moisture as it undergoes starch retrogradation.

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Flavor Appeal

While the bulk of pasta and rice dishes consist of the carbohydrate base, it's the flavor system or sauce that differentiates the products and promotes their appeal. These can range from simple, dried-spice systems to technically challenging sauces prepared to withstand rigorous processing or usage requirements.

"Overall, the trend is for strong flavors," says Jennifer Morgan, senior food technologist, Heller Seasonings & Ingredients, Inc., Bedford Park, IL. "Hot is still popular, but the associated flavor profile changes. You can get hot Southwest or hot with peanut sauce for Thai food. Indian food is gaining popularity, and we may be seeing more African flavors."

The flavor inspiration can come from popular restaurants, recipes or collaboration with chefs, but according to Morgan: "One of the most challenging parts is to develop a sauce in the kitchen, and then change the culinary version into a dry blend at the bench."

One of the most important considerations is the composition of the flavor system. These will be combined with a carbohydrate base and, although these are typically bland, some contribute characteristic flavors, such as brown rice or filled pasta. Their starchiness might mask or otherwise alter the flavor delivery. Thin, delicate pastas are complemented by lighter-flavored sauces, while a thicker ziti can carry a heavier meat sauce.

Product designers face a wide variety of flavoring ingredients with which to work. For example, with spices, fresh, frozen, dried, extracts, oleoresins and flavors are all available. Some work better in a given application - it's obvious fresh or frozen products would not work in a dry mix. But other issues arise. Fresh spices and seasonings might vary in character or intensity, while oleoresins or other natural or synthetic flavors deliver consistent flavor, especially if volatility is an issue. For visual impact, particulates from a dried or fresh spice will be required, and the flavor then can be standardized with oleoresin.

"If you are cooking a product longer," says Morgan, "you're going to want to use oils and oleoresins. If we were putting together a garlic-basil seasoning for a flavored pasta noodle, oils would have a greater impact after they undergo the rigorous drying and after the consumer boils the product. In a quick-cook product, you want to consider how the consumer will cook the product. You need ingredients that will rehydrate fairly quickly and have some tolerance in case the consumer doesn't follow the directions on the package."

Vegetables and, in some cases, fruits, often enhance pasta and rice dishes. The same issues arise as with spices: flavor consistency vs. appearance. So, while actual fruit and vegetable particulates lend eye appeal, if the product requires a strong carrot flavor, it might be wise to formulate with added flavors.

Fruits and vegetables come in a variety of formats. These have distinctive properties that dictate their use. Dry mixes require low moisture for shelf stability. Air-dried products rehydrate in seven to 15 minutes in boiling water, but they often lack color and flavor. Freeze-dried products rehydrate quickly - from almost instantly to about three minutes - and present an excellent appearance. But they're expensive, fragile and lack flavor. Intermediate products, like puffed vegetables, take about three to five minutes for rehydration. Piece size and temperature also affect the hydration rate of dried particulates; the larger the piece, or the lower the rehydration temperature, the longer the hydration takes. With a dry mix, the moisture level in the fruit or vegetable should match the total mix. However, too low a moisture might make the product brittle, and it could become too fragile to withstand filling and shipping. A higher-moisture, lower-water-activity piece, like an infused product, might be the answe

Another potential problem with vegetable and fruit pieces is even dispersion. In a dry mix, a two-stage filling operation can solve the problem by keeping separate the large vegetable particulates and the finer seasonings. In a "wet" mix, balancing the particle size and matrix viscosity ensures even dispersion, as does properly designed agitation and filling.

Click here to read Prepared Pasta and Rice Dishes Part - Two.

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