Principles Of Food Preservation Flashcards by Pournamy Paru1234

3 principles of food preservation

Removal/inactivation of microorganism
Inactivate enzymes
Insect, worm/ rat removal

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Micro filter materials

Asbestos pad
Porcalein
Diatomaceous earth

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Enzymatic changes happening by phenolase, ppo

Phenols—>orthoquinones—->melanin
Phenolic comp—-quinones (ppo)

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Who demonstrated heat preservation

Nicholas appert

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Most heat resistant pathogen? Its heat treatment?

C. Botulinum
Moist heat 100°C 10min

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Mild heat treatments

Pasteurization, blanching

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Sterilization temp and canning temp

100/121° C wet heat- 15min
82-100°C 7-10min
or >74° C @centre

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Blanching done prior to

Canning, freezing, dehydration

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D,F &Z value

Time- minutes.90% / 10factor reduction of living cell
Time- specific no of living cell destroyed at constant temp 121°C
Temp increment- increase rate of destruction 10folds or
Reduce D vactor by factor of 10

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Z value usually

8-12°C

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Radiations tgat cause vreaking of chem bobd

X and free el ctrons

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Recombined products and radicals during radiation

Hydrogen, hydrogen peroxide
H, OH and hydroperoxyl HO2 radicals

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Life time of radicals
Countries that approved radiation

10^-5 sec
38

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Radiolysis

Interaction and changes occuring by and on- IONISATION products on irradiated materilas

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Radiation standard doses
*No toxicological/ nutritional/microbiological problem: max avg dose & is given by……condidered stand dose by….
* Max recommended dose
*Acg dose….by…..

10kGy….JECFA….Codex alumentarius
15
10
WHO

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jECFA stands for

Joint FAO/IEAE/WHO Expert Committee on the Wholesomeness of Irradiated Food

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Irradiation doses for
1 sterilization of herbs and spices
2” long term storage of meat
3 packaging material- cork
4 inactivation or control- parasite- pork
5destruction of pathogen- spices, frozen poultry, shrimp, meat
6 disinfect- flour, grain, cocoa, pods
7 inhibit sprouting
8mould control- soft fruits,
9 extent shelf life - soft fruits, fresh fish, meat at 0-4°C

7-10kGy
>= 50
10-25
0.1-6
2.5-10
0.1-2
0.1-0.2
2-5
2-5

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Food usuitable for
1irradiation
2 freeze drying

1 dairy products and meat- rancidity
Vacuum packing
2 fatty food- melts and equipment inpairmnt

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What accelerates unsuitableness of dairy prdts fir itradiation

Presence of oxygen

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Order of sensutivity of water soluble vitamins
“ Fat soluble

TAP R FC B- B1, C, 2, 12, 9, 12, 7
EC AK D_ E CAROTENE,

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Canning by….year….book…

Nicholas appert
1804
The art of preserving animal and veg substances for a many years

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Low acid food….acid associated

> 4.6 ph
5% acetic acid

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Browning preventing in blanching
SO2
Citric acid
Salt
……are mixed and effective to prevent loss of colour, texture, flavour

2000-4000ppm 2-5min
1-2%

Sugar, ascorbic acid, citric acid

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…inhibits the enzyme….and refuce quinones in blanching

Ascorbic acid
Peroxidase

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Dehydrated products are called.../...

High acid high sugar High value low vol

Difference between- drying, dehydration, evaporation

Sun Controlled condtn Liquid---liquid, surface loss

Drying ratio/ dehydration ratio Viscous/ paste / aticky materials dried tgrough

Water content/ dry matter Drum dryers

Mechanism or graph of drying/ dehydration

AB-BC-CD Initial to wet bulb temp Constant rate perood, wet,max water activity =1, till critical mc Falling rate period- dry, water act<1, till eq mc

Mechanism or graph of drying/ dehydration

AB-BC-CD Initial to wet bulb temp Constant rate perood, wet,max water activity =1, till critical mc Falling rate period- dry, water act<1, till eq mc

Freezing/freeze storage temp Quick and slow

-18_-35/36°C -17.8_-46.6 -15_-29 Quick better...small crystal

Freeze concentraion happens in....

Freezing ....un crystalised portion gets saturated and water activity reduces..mo growth stops

Mo are killed by freezing Growth completely stops by freezing Enzymatic and non enzymatic avtions are arrested by freezing

False True False

Drying rate d/o Freezing d/o

Air vel Surf area Temp Shape Dimension/ size Thermal prop Freezing med's temp

Drying rate d/o Freezing d/o

Air vel Surf area Temp Shape Dimension/ size Thermal prop Freezing med's temp

Stages of freezing

Cooling to fp ( remove sensible heat) Freezing ( remove latent heat) Cooling to sub freezing tem (remove sensible heat of froxen food)

Freezing curve

Ab- supercooling, below fp but no frexing, nucleation BC: crystal formation proceeds, latent heat of crystallisation produced CD: major ice crystal formations, release of latent heat of crystallisation DE: EUTECTIC POINT, super saturation of solutes, and crystallisation of solutes, latent heat of crystallisation of solutes produced EF: release of lh of cry of solutes FG: mixture of ice and water Temp= temp of freezing medium

Cryodesication, lyophilisation is another name of

Freeze drying

Steps in freeze drying and temp used in each step

Freezing below fp Sublimation below tripple point Desorption more than 1° drying temp Usually 10-35°C for sensitive food and 50 °C for insensitive food

...% of water is removed during sublimation/1° drying and ....% remains in end product of freeze drying

95% 1-4%

...step removes frozen water and .... Step removes unfrozen water @ vacuum

Sublimation Desorption drying

Best drying method with Less colour, flavour, appearence loss No shrinkage No case hardening High rehydration ratio... In

Freeze drying Rehydration ration: 4-6times more

1° and 2° drying temp decided based on....& .... Resp Annhealind done to produce...ice crystals

Latent heat of sublimatoon Adsorption isotherm Large ice crystal Ostwald ripening: small ice crystalls lightly melted and then freezed to form large ice crystals

1° and 2° drying temp decided based on....& .... Resp Annhealind done to produce...ice crystals

Latent heat of sublimatoon Adsorption isotherm Large ice crystal Ostwald ripening: small ice crystalls lightly melted and then freezed to form large ice crystals

Microwave freq or wavelengths

300MHz- 300GHz 1mm- 1m

For food microwaving .... Half of initial energy of ^ is lost when penetrated....and...mm resp

2450-915/900MHz 10-76mm

Loss factor increase indicates

Higher degree of penetratiin, higher heat production/ absorption Highly lossy

Loss factor of 1 ice (-12°C) 2 distilled water 3 beef 4 ham 5 paper 6 polyethylene Potato raw Potato mashed 9 water + 0.5 M nacl

0.003 12 12 23 0.15 0.003 16 24 32

Electronic tube producing high freq radiant energy is ... And unit....

Magnetron KW

Soybean fermentation products....,....,.... Antinutritional factors (3) Benefit of soybean ferm

Tempeh Natto, moromi Trypsin inhibitor Phytic acid Reduce anti nut factors Hydrolyse proteins to simpler forms

Fermented products through: lactic acid fermentation Acetic acid ferm Mould ferm Alcohol/ yeast

Pickles, sauerkraut, kimchi, olive Vinegar, kombucha Soy sauce, tempeh, moromi, meso, cheese Bread, wine, beer

...bac can act only on alcohol or after yeast/ anaerobic fermentation

AAB Ethanol/ alcohol---acetic acid

... Can act only on glucose and not on starch/ lactose

Yeast

Brine conc and lactic acid conc in sauerkraut and olive

2.25% 1.8-2.3% 10%

Sauerkraut bacts and their products Ultimate ph

Leuconostoc mesenteroides --- LA+ AA+ carnondiox Lb brevis---> Lb plantarum Less than 4ph

Olive

Leuconostoc mesenteroides ---> Lb plantarum & Lb brevis

Yoghurt Bac Products Making Acetaldehyde produced by What products are inter benefiting

Streptococcus thermophilus: formic acid + CO2 Lb bulgaricus: aa, LA, acetaldehyde, co2 40-45°C 2%starter 3-5hr 5°C Lb bulgaricus Formic acid by S. Thermo and amino acid by Lb bulgaricus

Ph of yoghurt Of kombucha Sauerkraut Vinegar

4.4-4.6 3.5 <4 2.5-3.5

Ultimate ethanol content in beer Ale Lager ( organism and temp)

3-8% S. Cervicea, 12-18 deg c S, carlsberghensii 8-12 deg c

2 stage fermentaion seen in..., ....& ...

Wine and vinegar, kombucha

Malolactic fermentation occurs in..... By...

Wine LAB

Spoilage org of bread are Ropey bread by

Rhizopus stolonifer Neurospora sitophilus Bacillus subtillis-

In bread: evaporative loss of .... To increase shelf life of bread... And ... Are used

Ethanol or alcohol Calcium propionate and ascorbic acid

... Is a bac which can tol high salt conc and is gram... ...is a bac which is acid tole and is gram...

LAB, + NON spore forming AAB, -, OBLIGATE AEROBE

Probiotic bac are Other lb bac are

Lb pl-ac- rh Plantarum Acidophilus rhamnosus Bifidobacterium bifidum, longum Sac- bowl Saccharomyces boulardi Pediococcus acidilactici Leuconostoc Lb Lc Streptomyces Pediococcus Oenococcus Enteeococcus

No starter needed....depends on natural flora

Sauerkraut Olive Pickle

Mother/ mushroom/ .... Is associated with .... AAB asscociated with this is ...

SCOBY KOMBUCHA glucanacetobacter xylinus

Mould in soybean /meso/moromi production Moromi needs ..-..% ... Addition of salt soln: on soy sauce

Aspergillus oryzaa/koji mold 17-19%

Class of org involved in soy sauce And are

LAB Yeast Mold ( except AAB) LAB Lb delbrueckii Pediococcus soyea Yeast S cervisceae Torulopsis sp Mold Aslergillus oryzae

Substrate for soy sause are

Soybean and wheat Complex sugar to simple

Substrate for tempeh and cheese

Protein & CH---- texture and flavour Milk lipids----methyl ethyl ketones+ structurally altered proteins

Pediococcus involved in ... And ... Leuconostoc involved in ... And ...

Soysauce & olive (P. Cervisceae) Suerkraut & olive

Org in tempeh This fermentation is done to improve shelf life in tempeh

Mold- Rhizopus oligosporus No...nutritional quality and acceptance

Org in tempeh This fermentation is done to improve shelf life in tempeh

Mold- Rhizopus oligosporus No...nutritional quality and acceptance

S rouxii involved in ....

Soy sauce Not S cervisceae