Food safety and sanitation considerations

Группа 3тх

Дата – 15.05.2020

Дисциплина – Иностранный язык (английский)

Время проведения занятия – 13:15-14:50

Преподаватель – Рогова Ольга Викторовна

Тема учебного занятия: Остывание и хранение полученной хлебобулочной продукции.

1. Прочитать и устно перевести текст (приложение 1).

2. Просмотреть видеоматериал по теме занятия:

https://www.youtube.com/watch?v=VrUdtzXquWk&t=56s

https://www.youtube.com/watch?v=QH40-ZBkmSQ

https://www.youtube.com/watch?v=NBI_sUP-Uso

3. На основе прочитанного и просмотренного материала письменно ответить на вопросы и перевести на русский язык (приложение 2).

4. Выполненное домашнее задание необходимо предоставить в любом доступном формате (скан, фотография, документ MS Word) преподавателю либо по электронной почте olga.rogova.70@bk.ru, либо в личном сообщении в Вконтакте в срок до 09:00 19.05.2020.

ВНИМАНИЕ!!! Название файла (сообщения) должно содержать дату урока, фамилию студента и группу. Например: 15.05. - Петрова И – 3ТХ.

 

 

Приложение 1

    Bread Cooling

What is Bread Cooling?

Bread cooling is a self-explanatory concept, although it involves a lot of science. The main goal of cooling is to decrease the internal temperature of the baked bread from 93–97°C (200–208°F), at depanning or coming out of the oven, to 32–43°C (90–110°F). This step allows the finished product to achieve optimum keeping quality and comply with legal moisture limit of 38%.

Bread can be cooled either:

• Manually by placing on cooling racks after depanning (ambient or natural cooling)
• Automatically using racks, trays, or continuous conveyor belts (or spirals in wholesale breadmaking operations)

As the loaf cools, some of the moisture moves toward the crust which becomes softer or leathery unlike the hard shell it acquired in the oven. Cooled bread is immediately sliced, bagged or packaged.¹

How does it work?

Bread cooling is a mass and heat transfer unit operation. During cooling, baked bread loses moisture and dries out due to differences in water content between the crumb (higher moisture content) and crust (lower moisture in exterior part that is exposed to convective cool air currents).²

This moisture gradient allows the water to escape (i.e. diffuse) as vapor from the product to the micro-atmosphere of the cooling equipment. This vapor can readily condense as a function of the dew point.

The temperature gradient, between product’s core (higher temperature) and cooling environment (lower temperature) causes the product to lose heat to the surroundings. This gradient is at its maximum at the end of baking and beginning of cooling, but decreases to reach zero with progressive cooling.²

Molecularly, cooling causes the amylose fraction of starch to retrograde, i.e. to re-crystallize almost completely in order to set the crumb texture. This transition is key and makes possible the bread slicing operation, a result of the loaf firmness and set shape without collapsing under the cutter’s mechanical action.³

Application

Bread cooling time is a function of the size and shape of the loaf as well as the oven baking profile. Denser and bigger pieces require longer cooling times (slowing conveyor speed while maintaining other cooling variables).

Cooling variables that require adequate control include:

• Cycle time (related to conveyor speed in continuous operations in spiral conveyor coolers)
• Relative humidity and temperature
• Air flow (convection cooling)

Food safety and sanitation considerations

Proper sanitation minimizes microbial contamination of bread and prevents the growth of mold, bacteria, and wild yeast in the packaging area. Since bread is sterile when it exits the oven, contamination occurs during cooling, slicing, and packaging.