The Flow of Food: an Introduction Chapter Number 5 The Flow of Food: an Introduction

Learning Objectives After this presentation, you should be able to complete the following Learning Outcomes 5.0 5.1 Ways of preventing cross-contamination 5.2 Ways of preventing time-temperature abuse Different types of temperature-measuring devices and their uses 5.3 At the end of this lecture each student should have a general understanding of the chapter contents and a firm ability to accomplish the learning outcomes on this slide. How to calibrate and maintain different temperature-measuring devices 5.4 5.5 General guidelines for thermometer use

5.0 KEY TERMS • Flow of food: Path food takes through an operation, from purchasing and receiving through storing, preparing, cooking, holding, cooling, reheating, and serving. • Bimetallic stemmed thermometer: The most common and versatile type of thermometer, measuring temperature through a metal probe with a sensor in the end. Most can measure temperatures from 0° to 220°F (–18° to 104°C) and are accurate to within ±2°F or ±1°C. They are easily calibrated. • Thermocouples: Thermometers that check food temperature through a sensor on the tip of a metal probe. • Thermistors: Thermometers that check food temperature through a sensor on the tip of a metal probe. • Time-temperature indicator (TTI): Time and temperature monitoring device attached to a food shipment to determine if the product’s temperature has exceeded safe limits during shipment or subsequent storage. • Calibration: Process of ensuring that a thermometer gives accurate readings by adjusting it to a known standard, such as the freezing point or boiling point of water.

• Ice-point method: Method of Boiling-point method: Method of 5.0 KEY TERMS • Ice-point method: Method of calibrating thermometers based on the freezing point of water. Boiling-point method: Method of calibrating a thermometer based on the boiling point of water.

Ways of Preventing Cross-Contamination 5.1 Ways of Preventing Cross-Contamination CROSS-CONTAMINATION Many things can happen to food as it moves from purchasing and receiving through storing, prepping, cooking, holding, cooling, reheating, and serving. This path is known as the flow of food.

Ways of Preventing Cross-Contamination 5.1 Ways of Preventing Cross-Contamination CROSS-CONTAMINATION Cross-contamination is a major hazard in the flow of food. Pathogens can be spread from food or unwashed hands to prep tables, utensils, equipment, or other food. Cross-contamination can occur at almost any point within the flow of food. When you know how and where it can happen, it is fairly easy to prevent.

Ways of Preventing Cross-Contamination 5.1 Ways of Preventing Cross-Contamination GUIDELINES FOR PREVENTING CROSS-CONTAMINATION Using separate equipment Use separate equipment when preparing each type of food. Colored cutting boards and utensil handles can help you keep equipment separate. Cleaning and sanitizing Clean and sanitize all work surfaces, equipment, and utensils after each task. Pathogens, such as Salmonella spp., can contaminate food through cross-contamination.

Ways of Preventing Cross-Contamination 5.1 Ways of Preventing Cross-Contamination GUIDELINES FOR PREVENTING CROSS-CONTAMINATION (cont.) Prepping food at different times When using the same table to prep different types of food, prep raw meat, fish, and poultry at different times from ready-to-eat food so that the chance for cross-contamination can be minimized. Buying prepared food Buy food items that do not require much prepping or handling.

Ways of Preventing Time-Temperature Abuse 5.2 Ways of Preventing Time-Temperature Abuse TIME-TEMPERATURE CONTROL Time-temperature abuse is another major hazard in the flow of food. TCS food has been time-temperature abused any time it remains between 41° and 135°F (5° and 57°C). This is called the temperature danger zone because pathogens grow in this range. They grow especially fast between 70°F and 125°F (21° and 52°C).

Ways of Preventing Time-Temperature Abuse 5.2 Ways of Preventing Time-Temperature Abuse TIME-TEMPERATURE CONTROL TCS food is being time-temperature abused whenever it is handled in the following ways: Cooked to the wrong minimum internal temperature Held at the wrong temperature Cooled or reheated incorrectly  Time also plays a critical role. The longer food stays in the temperature danger zone, the more time pathogens have to grow. To keep food safe, you must reduce the time food spends in this temperature range. TCS food must be thrown out if it stays in the temperature danger zone for four hours or more.

Ways of Preventing Time-Temperature Abuse 5.2 Ways of Preventing Time-Temperature Abuse AVOIDING TIME-TEMPERATURE ABUSE Food handlers should avoid time-temperature abuse by following good policies and procedures. The ones you establish should cover the following areas: Monitoring Learn which food items should be checked, how often, and by whom. Assign duties to food handlers in each area. Make sure they understand what to do, how to do it, and why it is important.

Ways of Preventing Time-Temperature Abuse 5.2 Ways of Preventing Time-Temperature Abuse AVOIDING TIME-TEMPERATURE ABUSE Tools Make sure the correct kinds of thermometers are available. Give food handlers their own thermometers. Have them use timers in prep areas to check how long food is in the temperature danger zone. Recording Have food handlers record temperatures regularly. Make sure they write down when the temperatures were taken. Provide sample forms for recording this information next to cooking and holding equipment.

Ways of Preventing Time-Temperature Abuse 5.2 Ways of Preventing Time-Temperature Abuse AVOIDING TIME-TEMPERATURE ABUSE (cont.) Time and temperature control Have procedures that limit the time food spends in the temperature danger zone. Corrective actions Make sure food handlers know what to do when time and temperature standards are not met.

Different types of temperature-measuring devices and their uses 5.3 Different types of temperature-measuring devices and their uses CHOOSING THE CORRECT THERMOMETER The most important tool you have is the thermometer. There are many types of thermometers. Three types are commonly used in operations: Bimetallic stemmed thermometers Thermocouples Thermistors

Different types of temperature-measuring devices and their uses 5.3 Different types of temperature-measuring devices and their uses BIMETALLIC STEMMED THERMOMETERS Checks temperatures from 0° to 220°F (–18° to 104°C) Use it to check food temperatures both during receiving and in a hot- or cold-holding unit. When checking temperatures, insert the stem into the food up to the dimple for proper reading. Useful for checking the temperature of large or thick food. Not practical for thin food, such as hamburger patties. If you buy bimetallic stemmed thermometers for your operation, make sure they have the following features. Calibration nut Easy-to-read markings Dimple

Different types of temperature-measuring devices and their uses 5.3 Different types of temperature-measuring devices and their uses THERMOCOUPLES AND THERMISTORS Thermocouples/ thermistors Check temperatures through a metal probe and display digitally Sensing area on the tip of their probe. Not necessary to insert them into the food as far as bimetallic stemmed thermometers Good for checking the temperature of both thick and thin food

Different types of temperature-measuring devices and their uses 5.3 Different types of temperature-measuring devices and their uses INFRARED THERMOMETERS Infrared (Laser) Thermometers Measures the temperatures of food and equipment surfaces Quick and easy to use as they do not need to touch a surface to check its temperature Less chance for cross-contamination and damage to food Cannot measure air temperature or the internal temperature of food Follow these guidelines for using infrared thermometers. Distance Hold the thermometer as close to the food or equipment as you can without touching it. Barriers Remove anything between the thermometer and the food, food package, or equipment. Avoid taking readings through metal, such as stainless steel or aluminum. Do not take readings through glass. Manufacturer’s directions Always follow the manufacturer’s guidelines for most accurate readings.

Different types of temperature-measuring devices and their uses 5.3 Different types of temperature-measuring devices and their uses TIME-TEMPERATURE INDICATOR (TTI) Time-temperature indicator Attached to packaging by the supplier A color change appears in the TTI window if the food has been time-temperature abused during shipment or storage. This color change is not reversible, so you know if the item has been abused. Some suppliers place temperature-recording devices inside their delivery trucks.

Calibrate and maintain different temperature-measuring devices 5.4 Calibrate and maintain different temperature-measuring devices HOW TO CALIBRATE THERMOMETERS Thermometers can lose their accuracy when they are bumped, dropped, or experience severe temperature change. There are two ways to calibrate a thermometer: ice-point method boiling-point method

Calibrate and maintain different temperature-measuring devices 5.4 Calibrate and maintain different temperature-measuring devices HOW TO CALIBRATE THERMOMETERS Boiling-Point Method To calibrate a thermometer using the boiling-point method, follow these steps: Bring clean tap water to a boil in a deep pan. Put the thermometer stem or probe into the boiling water. Make sure the sensing area is submerged. Wait 30 seconds or until the indicator stops moving. Do not let the stem or probe touch the container. Adjust the thermometer so it reads 212°F (100°C). This temperature will vary depending on the boiling point for your elevation. Water’s boiling point is about 1°F (about 0.5°C) lower for every 550 feet (168 meters) above sea level.

Calibrate and maintain different temperature-measuring devices 5.4 Calibrate and maintain different temperature-measuring devices HOW TO CALIBRATE THERMOMETERS Ice-Point Method Thermometers are often calibrated using the ice-point method. Follow these steps to use this method.

General guidelines for thermometer use 5.5 General guidelines for thermometer use GENERAL THERMOMETER GUIDELINES Cleaning and sanitizing Thermometers must be washed, rinsed, sanitized and air-dried before and after use. Keep storage cases clean as well. Calibration Calibrate thermometers before each shift and before the first delivery arrives. Accuracy Food thermometers need to be accurate to +/- 2°F or +/- 1°C. Air temperature/food storage equipment need to be accurate to +/- 3°F or +/- 1.5°C.

General guidelines for thermometer use 5.5 General guidelines for thermometer use GENERAL THERMOMETER GUIDELINES (cont.) Glass thermometers Glass thermometers, such as candy thermometers, can be a physical contaminant if they break. They can only be used when enclosed in a shatterproof casing. Checking temperatures When checking the temperature of food, insert the thermometer stem or probe into the thickest part of the food. Take another reading in a different spot. The temperature may vary in different areas. When using a bimetallic stemmed thermometer, insert the stem all the way into the food from the tip to the end of the sensing area. When checking the internal temperature of thin food, such as meat or fish patties, use a small diameter probe. Before recording a temperature, wait for the thermometer reading to steady.