Restaurant fryers

The principal categories of restaurant fryers are (1) countertop fryers, (2) floor-type fryers, (3) pressure fryers, and (4) turkey fryers. 

A typical restaurant fryer operates at 335-375°F (168-190.6°C). A measured amount of food is placed in the basket. The basket is lowered into the oil, which is already heated to the desired temperature. The oil temperature in the fryer drops immediately, and then it gradually recovers. The recovery time for the oil temperature within a specific time is critical for French fries, coated vegetables, and so on to achieve the desired product texture, flavor, and appearance. However, the recovery time for the fryer oil temperature is especially critical for chicken, fish, and other meat products, where the interior of the product must reach a specific temperature to prevent food-bome diseases associated with the meat and poultry products. 

Depending on the product, the restaurant fryers are operated at 335 to 375°F (168-190.6°C). During slow hours, the fryers are maintained on standby mode to keep the oil temperature relatively low. The oU is always maintained at the frying temperature during rush hours. 

TABLE 4. Regulatory Guidelines on Restaurant Fryer Oil in Various Countries. 

The early test methods used to determine the point of discard for the oU in a restaurant fryer are as follows ... 

Color wands and color strips were promoted to determine the oil quality in a restaurant fryer. These did not provide any practical help to the restaurant personnel because a universal color standard does not apply for all types of oil. Sometimes, cottonseed od, com oil, and palmolein turn darker than soybean or sunflower oil in a restaurant type fryer, even though the oil quality is perfect for frying foods. In such cases, the restaurant operator may discard the good quality fryer oil just because the color may appear dark to the restaurant operator. 

The 3M Company of St. Paul, MN introduced the Shortening Monitor, which consists of a white strip of paper, measuring 0.3 x 3.75 inches, which has four blue bands across it. The strips are used as a dip test to measure accumulated free fatty acids in the oil. The tests were developed to provide users, especially those in the fast-food industry, with an inexpensive means to objectively measure FFA in the cooking oil. This test might be suitable for restaurants because the FFA in restaurant fryers tend to mn high and might be effective to predict the imminence of reduced smoke point in the fryer oil. 

The restaurant fryers do not have oil cooling capability. The operators do not normally check the oil temperature before the treatment material is added to the oil. Thus, one can expect less than desirable results from the oil treatment. 

These fryers resemble the so-called restaurant fryers, except they are much larger in size, capable of frying several hundred pounds of product per batch. Figure 7 shows the picture of a typical batch fryer. 

The restaurants and food services consume the fried products soon after their preparation. Therefore, the shelf life of the product is not a significant factor for these products. The industrial products are sold in various types of packages that protect the products from becoming rancid during storage and distribution. The oil in the restaurant fryer degrades rapidly because of the constant exposure to high temperature and the extended hours of idle time. The continuous fryer... 

Fryers are typically used for frying fish, chicken, or French fries in restaurants. The basic soil is oil and fat, with some meat, fish, or potato, in part burnt-on or carbonized. Owing to the bumt-on or carbonized nature of the soils, a heavy-duty alkaline degreaser is used for cleaning. Generally, a restaurant fryer is boiled with water at 165°F and heavy-duty degreaser for several hours, drained, rinsed, and scrubbed to remove difficult soil [68]. Finally the fryer is washed with acid to neutralize any alkaline residue. 

Restaurants also use batch fryers, where the food is placed in a wire basket, which is lowered into a bed of hot oil. The basket is removed from the hot oil when the product is fully fried. 

Restaurants, fast food restaurants, and the food services use a wide range of precooked or par-fried products. This includes products such as (1) French fries and (2) batter-coated and par-fried fish, chicken, meat patties, cheese sticks, vegetables, and so on. These products are taken out of the freezers and placed directly in the bed of hot oil in a fryer without thawing. 

Countertop pressure fryers (see Figure 2) are especially suitable for frying batter-coated fish or shrimp in small restaurants and as experimental fryers for research work. These fryers have a single pressure setting and an automatic shutoff device. 

It is necessary to Alter the fryer oil at some regular frequency. This is done to remove the particulate matter that accumulates in the oil, which makes the oil become dark. The product begins to exhibit a burnt odor or flavor if these particles are left in the oil. The accumulated particles can also act as catalysts for oil degradation, increasing the risk of Are hazards at the restaurants. 

External filters are also used to filter the fryer oils. These filters are similar in principle to the built-in filters. Operation of these filters is hazardous because of the high oil temperature and manual handling of the hot oil. Burns from the hot oil is one of the common accidents in the fast food restaurants. Figure 4 shows the schematic diagram for an external filter. 

Since 1998, the CSPC has reported 75 incidents that involved fires, flames, or burns associated with turkey fryers. Twenty-eight of these incidents were reported for the year 2002. Turkey fryers are becoming popular. These fryers can be seen in many fast food restaurants, frying either whole turkey or chicken. Therefore, the users of this type of fryer must be aware of the safety tips offered by the agency. The detail of this report can be found on the website of the agency. 

It is possible to maintain high quality in fryer oil and that of the fried food in a restaurant by applying the following procedures ... 

It is difficult to decide on oil discard. The restaurant manager or a senior employee decides when the oil from a fryer should be discarded. 

Traditionally, the restaurants have used oil color or the foam height in the fryer to decide on oil discarded. However, both approaches are subjective and can lead to either premature discarding of the oil or the use beyond its limit for optimum product flavor and taste. 

A few instmments to measure oil degradation have recently been introduced. They mostly measure the oil decomposition products commonly referred to as polar compounds. Researchers are testing these instruments to determine their applicability for evaluating fryer oil quality in the restaurants. 

The USFDA has not imposed any regulation on frying oil quality at restaurants or in the industrial frying operations. The USDA requires the fryer oil to be discarded when the free fatty acid (FFA) in the oil exceeds 2%. 

Most countries in Europe and Chile have adopted some form of regulations to control the quality of frying oil at the restaurants. Most of these countries have decided that the oil reaches the end point when the polar material in the oil exceeds a certain level. This level is somewhat different for different countries. This regulation compels the restaurant personnel to learn the techniques of testing fryer oil for quality and to determine when to discard it. Table 4 lists the regulatory limits on the restaurant oil quality (3). 

Several inventors have developed instruments for measuring fryer oil quality. Unfortunately, some of them are too complex to operate, whereas others can be applied in monitoring the oil quahty in restaurants. These instruments are as follows ... 

The Merck Company of Darmstadt, Germany developed the OXIFRIT FRIT-EST to measure oil quality in frying operations, especially in restaurants. The Fritest measures the alkali color number to indicate oxidized fatty acid (OFA) and the Oxifrit Test measures oxidation products in the fryer oil. Both tests are colorimetric and use a solvent-based reagent system. The test methodology is too comphcated for the restaurant personnel. 

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