Inside kitchens: equipment for frying
From inefficient oil filtering and unhealthy contaminants to personnel hazards and responsible oil disposal, plenty of concerns confront caterers buying and using deep-fat fryers. Bruce Whitehall asks suppliers for their views on the best options for improved frying management
Immersion in hot oil or fat doesn't just contribute flavour and succulence to food, it also adds plenty of complications. These include safety (burns, extra-slippery floors and flash fires), environmental (clogged fume extractors and drains) and perceived health risks (such as acrylamide, toxins and trans-fatty acids, to say nothing of extra calories and cholesterol).
With chips and battered foods virtually indispensable on many menus, are caterers doing enough to minimise the risks? Leading equipment suppliers believe that some issues have been blown out of proportion, such as the notion that poorly maintained equipment can exacerbate levels of potentially carcinogenic acrylamide in fried food.
Nick McDonald, marketing and export director of Lincat, dismisses such talk as "deplorable scaremongering", pointing to scientific studies that show acrylamide occurring in all kinds of starchy foods cooked at 100°C or more when roasting, baking and microwaving as well as frying. In fact, a Swedish study found that 54% of daily acrylamide intake derived from coffee, while only 12% resulted from fried potatoes. And, in any case, studies suggest no link between normal human acrylamide intake and cancer.
Rather more worrying are trans-fatty acids, which are mainly found in vegetable oils that have been subjected in manufacturing to a hardening process called partial hydrogenation. Such oils have been popular since the 1970s for deep-frying, thanks to their longer life and robustness in use. However, research has suggested that trans fats contribute significantly to raised cholesterol levels and heart disease. The World Health Organisation has recommended that governments around the world should seek ways to phase out partially hydrogenated oils.
Large purveyors of fast food have already started to consider limits. For example, the Walt Disney Company last month announced that it will remove trans fats from food at its parks by the end of 2007.
With consumers encouraged to ask about the presence of trans fats in the food they order, food service operators "must accept the responsibility of either serving healthier fried foods or being prepared to explain why they do not", comments Paul Williams, managing director of ServEquip, which supplies the Henny Penny equipment widely used in fried chicken and other fast-food outlets.
Williams points out that some newer frying oils, such as high oleic canola and low linolenic soybean, can offer excellent performance with low or no trans fat content. He concedes that higher costs can impact on margins but emphasises that better frying practices, from push-button oil filtration to automatic melt and idle modes, can help keep these in check. For example, Henny Penny fryers have an optional filter enforcement function to signal the need to filter after a set number of cooks or at certain times of the day. This can be programmed to suppress fryer operation to guarantee that filtration is actually carried out.
Malcolm Morris, marketing manager of Valentine Equipment, agrees that daily filtering is important to ensure longer oil life, less contamination and better-tasting food and thinks that built-in filtration systems, offered optionally on Valentine's self-standing fryers, make it a lot easier to ensure that the job gets carried out.
The main snag is the extra £500-plus per fryer (plus a similar amount again if computer control is fitted). While the big international fast-food chains have routinely invested in such bells and whistles, most other caterers are still reluctant. And, whatever equipment is in place, use still needs to be policed. "If management is not up to scratch, oil quality can be poor," Morris observes. "At one group site I visited recently, ‘crumb' waste matter - which is potentially carcinogenic - covered the bottom of the elements. Yet the site standards manual provided by senior management only scheduled fryers to be cleaned and filtered once a week."
Research carried out by Enodis suggests that a major reason for users not to filter or change oil regularly is downtime. With the Frymaster series of high-output fryers, steps have been taken recently to make the process simpler and quicker - less than five minutes to filter a tankful of oil in use and 15 minutes for a complete oil change.
"No longer is it acceptable to use the same oil for weeks on end, as this will lead to soft, oil-heavy food and unimpressed customers," comments Ian Osborne, group managing director of Enodis UK Foodservice. But he also emphasises the need for consistent staff education on such basics as correct loading and unloading of baskets, draining off of excess fat, frying food for the full time at the correct temperature, and awareness of smoke points, which influence speed of oil degradation and consequent flavour of fried foods.
Taste transfer can also be reduced with an effective built-in filter system, according to manufacturer Imperial, which fits a pump able to shift oil at up to 23 litres per minute. Imperial claims that the three-tube heating system on its Elite Fryer has a higher BTU rating than any other fryer. Heating the oil quickly limits absorption of oil by the food, resulting in a better-tasting product on the plate.
In common with most makers of high-volume fryers, Frialator International, supplier of Pitco fryers, advocates cool zones on its fryers, believing that they extend oil life by enabling sediment to fall down into a cooler environment below the burners where it cannot burn or coat food with carbon deposits.
Falcon Foodservice Equipment flatly contradicted such arguments when it introduced its Infinity gas fryers last year. These have flat-bottomed tanks that save costs by needing less oil (16 litres compared with 25 litres-plus on other fryers with comparable outputs). To cope without a cool zone, daily filtering is made as easy as possible, with an integral filtering system that deals with the hot oil without any cool-down delay.
"With a flat-bottomed fryer, oil obviously has to be filtered more frequently," argues Frialator group sales manager Gary Richards. "There is nowhere for the sediment falling off the coated products to escape to." He claims that Pitco's cool zone is the largest on the market and allows oil to be used for longer between oil changes, reducing overall oil consumption when combined with an efficient filtering regime.
Falcon is unrepentant on its stance and this year boosted its fryer activities with addition of Swiss-made FriFri electric models, which also boast lower tank capacities than competitive models.
Aside from high-volume fast-food outlets, most caterers tend to see frying in terms of basic fryers - self-standing or counter-top - costing hundreds rather than thousands of pounds. Ray Hall, managing director of RH Hall, recommends close attention to basic fitments, such as oil temperature indicators and drain taps, to ensure day-to-day safety. In terms of power supply, 13amp electric fryers offer the simplest siting option. Running cost differences between gas and electricity are now more or less negligible for the average operator, he suggests.
Enodis UK Foodservice
0845 370 4888
Falcon Foodservice Equipment
Imperial Catering Equipment
Lincat: 01522 875500
0845 390 9808
0118 957 1344