food tech

• Microbial spoilage of canned foods is a common problem.
• Microbial spoilage of cereals and cereal products is a significant issue.
• Microbial spoilage of fruits and vegetables is a prevalent problem.
• Food spoilage, defined as unacceptable to be eaten or consumed, involves biological, chemical, and physical changes that are preventable, detectable while food contamination is undetectable, and caused by microorganisms, enzymes, purely chemical reactions, insects, pests, and rodents.
• Microorganisms produce substances which alter the colour, texture and odour of the food, making it unfit/unsafe for human consumption.
• Enzymes are substances that are naturally present in food – responsible for the ripening process of fruits and vegetables or produced by microorganisms.
• Purely chemical reactions, not catalyzed by enzymes, include rancidity of fats and oils.
• Mycotoxins are a diverse group of chemical substances (secondary metabolites) produced by fungi.
• Aflatoxins are a group of highly poisonous and carcinogenic compounds, which are produced by strains of the fungi, Aspergillus flavus and Aspergillus parasiticus, on suitable substrates such as cassava, copra and other oilseeds, corn and peanuts.
• Patulin is a mycotoxin with a maximum limit of 50 μ g/kg or μ g/L for patulin in apple juice and apple juice ingredients in other beverages.
• Ochratoxin A is the toxic metabolite produced by fungi belonging to the genera Aspergillus and Penicillium specifically A ochraceus and P verrucosum.
• Fumonisins are produced by the fungi Fusarium verticillioides, F proliferatum, F moniliforme and other Fusarium species that grow on agricultural commodities in the field or during postharvest operations.
• Deoxynivalenol, commonly called vomitoxin, is produced by several fungi of the genus Fusarium specifically F graminearium frequently infecting barley, corn, oats, rice, and other cereals in the field or during postharvest operations.
• Zearalenone is the compound produced by Fusarium spp such as F graminearium and F culmorum found specifically as a contaminant in corn but may also occur in barley, oats, sorghum, and wheat.
• Mango stem end rot is a disease caused by the fungus Alternaria alternata.
• Cottony soft rot is a disease caused by the fungus Fusarium oxysporum.
• Fruit and stem end rots is a disease that affects avocado trees.
• Fusarium crown and foot rot is a disease that affects cucurbits.
• Stem end rot is a disease that affects brassicas.
• Black rot is a disease that affects brassicas.
• Fusarium fruit rot is a disease that affects cucurbits.
• Alternaria Fruit rot is a disease that affects solanaceous crops.
• Fusarium root rot is a disease that affects dry beans.
• Bacterial soft rot is a disease that affects vegetables.
• Brown rot is a disease that affects vegetables.
• Insects, pests, and rodents damage food making it more vulnerable to further damage and deterioration.
• Quantitative range for bacteria, molds, vegetables, and fruits is 10^3 - 10^7 CFU/g.
• Microorganisms isolated from product samples are approximate.
• Microbial spoilage may be due to plant pathogens acting on the stems, leaves, flowers or roots of the plant, on the fruits or other special parts used as foods, or saprophytic organisms after action of a plant pathogen or may enter a healthy fruit or vegetable.
• Types of spoilage include spoilage caused by plant pathogens, molds, and bacteria, and soft rot spoilage in vegetables.
• Passive or wound-induced spoilage can be caused by action of agents.
• Bacterial soft rot is caused by Erwinia carotovora and E. chrysanthemi and related species, which are pectin fermenters, and other causative agents such as Pseudomonas cichorii, Pseudomonas marginalis, and Clostridium and Bacillus spp.
• The mode of action of bacterial soft rot is that bacteria break down pectins, causing softness and mushiness, sometimes bad odour and water-soaked appearance of produce.
• Causative bacteria of bacterial soft rot will grow at 37 ° C but can withstand refrigeration temperatures.
• Gray mold rot is caused by Botrytis species, which produce gray mycelium of mold, and is induced by high humidity and warm temperature.
• Rhizopus soft rot is caused by Rhizopus species, which is spread by Drosophilia melanogaster
• Unbaked or partially baked products can be stored for months in the frozen condition.
• Ammonia (2%) & propionic acid (1%) reduce mold growth in high moisture corn.
• Sodium and calcium propionate, sodium diacetate, and sorbates are used extensively in breads, rolls, cakes, and other bakery products.
• Acidification of the dough with acetic acid has been used to combat rope.