Food technology marking

[sfernandoooo]

Hi i was wondering if you guys are able to look at my extended response for food tech. its due in 2 days.

Explain the principles of food preservation involved in production of TWO products:                                                                  10 marks

The principles of food preservation are interdependent on food’s ability to remain shelf stable for long periods. Manufacturers utilise the four principles of preservation, that is temperature control, restriction of moisture, exclusion of air and control of pH levels, to preserve the sensory characteristics and to prevent food deterioration. Notably, an example of the application of restriction of moisture and temperature control is the Frenchman Allais’s prolific invention of freeze-dried coffee. Restriction of moisture occurs during the first 3-5 minutes, at temperatures from 210˚C- 230˚C, where the bean loses its moisture. The roasting process restricts water evaporation within the bean, extending the coffee’s shelf-life, preventing  spoilage. Without restricting the bean’s moisture, the bean loses its taste, as correct moisture helps exquisite flavours to appear. Restriction of moisture destroys mycotoxins (mould) preventing food deterioration. Due to the moisture level restrictions, food manufacturers can preserve freeze-dried coffee. This is linked to temperature control, as beans roasting  at under 200 °C, are more acidic than ‘perfect roasts’. Darker bean roasting results in caffeine and pungent flavour loss. Freeze dried coffee products such as Nescafe, Moccona and Lavazza differ in flavour and colour consequently. The bean’s colour indicates temperature control, as roasting influences the colour. Colour is linked to flavor as intense heat is applied, bean compounds such as 2-furfurylthiol develop, giving its complex flavour. Caffeol is a volatile coffee essence developed in the bean at 200 °C,  impacting the bitter freeze-dried coffee. Without colour and caffeol the end product lacks the basic characteristics of coffee which is dependent on colour and flavour itself. Hence, restriction of moisture and temperature control aid food to be preserved to its best quality, as exemplified by freeze-dried coffee.

Another example of how principles of preservation is applied is Henry Gineca’s 1901 innovative canned pineapples. Canned pineapples use the principles of control of pH levels and exclusion of air to prevent microbial growth and to extend the shelf-life of pineapples. Inadequate pH application allows for growth of mesophilic microorganisms in pineapples. Featherstone (2015), surmises microbial spoilage in canned food is credited to food’s acidity as high acidity allows softened canned pineapples, decreasing the level of consumer appeal. Theoretically, the lower the pH, the more food acidity, and safer the canned pineapple is from food poisoning. Additives inhibit microorganisms, minimising food spoilage by denaturing microorganism’s enzymes. Approximately, a teaspoon of tartaric acid is added to preserve the pineapple mix and meet the safe pH level of 4.6 or below. The tartaric acid prevents microorganisms from growing. Control of pH levels achieves economic viability for producers by reducing seasonal fluctuations. Exclusion of air also impacts on canned pineapple’s shelf-life. To avoid the cooking necessity of  high-temperature food to exclude the air, various modifications are employed. Exposure to the air will cause the vitamin C loss and discoloured fruit. Self-seal types of jar lines are tightened firmly before processing to preserve quality vitamins and colours. Microbial organisms require oxygen to survive. Eliminating oxygen surrounding the pineapple prevents microbial organisms from re-entering the food’s environment. Consequently, failure to exclude air can welcome Clostridium, thus, food poisoning. Exclusion of air and temperature control are important to preserve food safe for human consumption and retain nutritional value.

Hence, the examples of canned pineapples and freeze-dried coffee confirms the interdependence between principles of preservation and the food’s ability to extend shelf life and become quality food.




Identify ONE suitable packaging material for EACH of the above products. Describe the functions of each of the materials in the packaging and its suitability to the product.                         10 marks                                         

Food packaging protects food from environmental effects of oxygen, light and moisture in storage and distribution to the consumer. In the early 1950’s, DuPont pioneered ‘Mylar’, a plastic manufactured from BoPET. Mylar is manufactured by coasting PET (Polyethylene terephthalate) with a metal layer, reducing the oxygen transmission rate by the impermeability towards gases. Without the metallic surface layer, coffee granules are vulnerable to spoilage as interaction with oxygen activates enzymes and oxidises the granules, aging coffee faster. Hence, reducing the shelf-life of freeze-dried coffee. Hence, the metallic layer is an indispensable that  preserves the freshness of freeze-dried coffee, extending its shelf life. Moreover, mylar bags consist of a metalised plastic sheet to reflect 95.5% of the light when exposed to the sun. Mylar is highly opaque, meaning that it blocks most of the light from interacting with coffee granules. Mylar’s high infrared reflectance acts as a barrier between light and food, preserving coffee’s pungent scent and piquant flavour. Without this feature, vital nutrients in coffee such as pantothenic acid and riboflavin will be lost from light exposure. Thus, mylar’s opaqueness makes mylar suitable for freeze-dried coffee as it preserves vital nutrients and physical characteristics. Similarly, mylar bags are designed to block 97% of the moisture from entering the product and deteriorating it. The two main raw materials of mylar bags are: ethylene glycol and terephthalic acid combined to form a compact molecular structure. The closely packed compounds construct a thick cellular wall, refraining moisture from entering the coffee granules, to sustain shelf-life. Hence, utilisation of mylar for freeze-dried coffee packaging achieves suitability as it prevents mould growth and spoilage of coffee.
 
Due to the time-consuming process of storage and distribution, there is a high chance for canned pineapples to increase in acidity as it sits between a 3 and a four on the pH scale, and reacts with the container. Glass is inert as it's built from non-reactive chemicals of  sodium oxide, borate and magnesium oxide, meaning there is no space for ascorbic acid to react with glass. Thus, the use of non-reactive chemicals in glass makes canned pineapple suitable for the purpose of safe consumer consumption. The impermeability of glass is an ideal feature for the sensitivity of canned pineapples that contain high acidity. Glass’s compact molecular structure makes it impermeable to CO2 and O2 gases. Impermeability of glass creates internal and external environmental barriers, restricting moisture from breaking down the pineapple’s molecular structure. Hence, impermeability is an effective characteristic in maintaining durability of the canned pineapples.Another characteristic that makes glass suitable for canning pineapples is its transparency for  consumers to assess the canned pineapples. Blackheart is a physiological disorder of pineapples that’s externally and internally undetectable. Pineapples affected by Blackheart show symptoms after a few weeks of being cut. Glass’s transparency ensures consumers can observe any unusual dark spot and assess purchasing  quality, which improves their safety.Thus, transparency of glass confirms its packaging suitability, allowing consumers to protect themselves from food poison and infectious diseases.