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FTSC 326 EXAM 2 COMPREHENSIVE STUDY
GUIDE 2026
◉ what are more process-tolerant verses vegetative cells. Answer: bacterial endospores (spores) ◉ the three "philics" that describe bacterial endospores. Answer: thermophilic, mesophilic, and psychrotrophic ◉ what are bacterial endospores. Answer: they are bacterial organisms that are gram positive ◉ c. bot and c. perfringens belong to what class of pathogenic organism. Answer: toxigenic clostridium spp. ◉ b. cereus and b. thuringiensis belong to what class of pathogenic organism. Answer: toxigenic bacillus spp. ◉ why are spores problematic for food safety in cooked foods and spoilage in foods.
Answer: they can survive cooking. they are important in low-acid foods (ph >4.6) packaged in cans, bottles, pouches, or other hermetically (vacuum) sealed containers (ex, canned foods) that are processed by heat. (Diseases and spoilage caused by sporeformers are usually associated with thermally processed foods, since heat kills vegetative cells but allows survival and growth of spore-forming organisms) ◉ psychrotrophic sporeformers cause spoilage of. Answer: refrigerated foods ◉ FDA and USDA define low-acid canned foods as one with a final pH of ____ and water activity of _______. Answer: >4.6; >0.85 (4.6 pH criterion for considered low acid food. C. botulism stops growth at) ◉ low-acid canned foods are packaged in hermetically (airtight) sealed containers. These cans must be processed by heat to achieve...... Answer: commercial sterility ◉ commercial sterility?. Answer: uses heat to inactivate foodborne pathogens and spoilage microorganisms that can grow in the food. It indicates a shelf-stable product with a negligible level of microbial survival.
Answer: 90%; 99.9% ◉ temperature change required to alter the D value by a factor of 10. Answer: Z value ◉ t/f acidification or aw (water activity) reduction can't produce commercial sterility. Answer: false (it can!) ◉ characteristics of clostridium botulinum. Answer: bacilli (rod shaped), obtain energy by fermentation, obligate anaerobe, neurotoxin (highly potent), pathogen of concern, foodborne intoxicating pathogen (adults) - causes botulism ◉ three species of Sporeformers of public health significance....?. Answer: C. botulinum, C. perfringens, and B. cereus (cause foodborne disease) ◉ B. cereus can produce a heat-labile enterotoxin causing ___ and a heat-stable toxin causing ___ in humans. Answer: diarrhea; emesis (vomiting)
◉ this sporeformer is widespread in soils and in the intestinal tracts of humans and certain animals. They grow extremely rapidly in high- protein foods. production of diarrheal enterotoxin. Answer: c. perfringens ◉ spores naturally present in foods and the cannery environment contribute to spoilage problems. dry ingredients such as ____, ___, ____,& ____ often contain high spore levels.. Answer: sugar, starches, flours, and spices ◉ spore populations can also accumulate in a food-processing plant, such as ______ spores on heated equipment and saccharolytic clostridia in plants processing sugar-rich foods such as fruits.. Answer: thermophilic ◉ the principal classes of sporeformers causing spoilage are thermophilic (listed on the slides. the book has others)..... Answer: flat-sour organisms, thermophilic anaerobes, putrefactive anaerobes, ◉ major sporeformer responsible for flat-sour spoilage? what are the defects?. Answer: thermophilic bacillus spp.
◉ describe thermophilic acid spoilage. Answer: spoilage of acid foods; gas production uncommon, but off odors and discoloration compounds produced ◉ what are the 7 spore layers. Answer: the exosporium, coats, outer membrane, cortex, germ cell wall, inner membrane, and core ◉ this layer protects the spore cortex form attack by lytic enzymes. Answer: spore coat ◉ this layer helps keep the spore impermeable to small molecules. Answer: outer membrane ◉ this layer mechanically dehydrates the core and is responsible for much of spore resistance (made up of peptidoglycan). Answer: cortex (The spore cortex is essential for creating and maintaining the dehydrated state of the spore core.) ◉ this layer has very low water content. Answer: core
◉ what about the core is responsible for spore dormancy and spore resistance. Answer: low water content ◉ Because dehydrated, heat transfer sufficient to kill is ____. The spore becomes more heat resistant as it dehydrates. Answer: limited ◉ spore's _____ helps it survive for extremely long period in the absence of nutrients.. Answer: dormancy ◉ They are much more resistant than vegetative cells. Their resistance is due to many factors such as spore core dehydration, small, acid-soluble proteins (SASP), and impermeability. ---SASP contribute by preventing DNA damage. Answer: ◉ go over the spore structure ***. Answer: ◉ spores are made in response to what 2 things. Answer: environmental stress or nutrient depletion
- GERMINATION is when spores lose most. Answer: ◉ microbiological criterion. Answer: Settings that are set that the food industry use for determining the process resulted in keeping the food desired. Confirmed by testing. (the microorganism or toxin must either not be present or present in only a limited number of samples less than a specified number or amount in a given quantity) ◉ Using Microbiological Criteria. Answer: Ensuring product safety Assessing safety of foods Acceptable-Unacceptable Quality and shelf life Following GMPs ◉ Components of Criteria. Answer: 1 Description of Food 2 Contaminant concerned 3 Analytical method 4 Sampling plan 5 Limits
◉ When do I want to Implement a Criterion?. Answer: 1. Responding to a safety need
- Evidence of health hazard
- Food can support microbial growth
- Need to assess sanitary conditions
- Protect RTE
- Little processing of ingredients (less safe)
- Improvement in public health
- Practical and useful!
- spoilage potential
- the potential for microbial contamination
- nature of the food's normal microbial makeup and ability of food to support microbial growth ◉ look and understand example of criteria on slide set (pasteurized milk, coliforms)***. Answer: ◉ Lack of criterion in certain ingredient. Answer: most likely caused disease before
Answer: used in process monitoring, conformance to GMPs, possibly also to determine processing adherence to critical control points (CCPs) ◉ Using Sampling Plans. Answer: - Help devise a system for collecting samples from lots
- Determination of product safety, quality
- Execution of microbiological criterion (CANNOT guarantee safety, but still helpful) ◉ example of sampling plan. Answer: Plan: 10 samples taken. Based on the decision criterion, only a certain number of the sample units could be positive for the presence of microorganism for the lot to be considered acceptable. If, in the criterion, the max allowable number of positive units had been set at 2 (c=2), a positive result for >2 of the 10 samples units (n=10) would result in rejection of the lot ◉ Lot. Answer: Amount produced under uniform conditions; one batch; specified period ◉ Sample. Answer: smallest unit of a lot
◉ Analytical unit. Answer: Amount of product actually undergoing analysis ◉ Defect. Answer: Unit not meeting requirements for microbe or toxin ◉ Attribute. Answer: qualitative available to measure a sample unit (this class focuses more on this type of sampling plan because it is preferred when microorganisms are not homogeneously distributed throughout the food or when the target microorganism is present at low levels. Widely used to determine the acceptance or rejection of products. Also used to monitor performance relative to accept GMPs.) ◉ describe 2 Class attributes plan. what is n, c, and m?. Answer: - identifies sampled lots as Acceptable or Defective
- often used for Pathogens vs. Hygiene indicators (non-pathogen testing) n = # samples collected c = max # defective samples m = # of target contaminants discriminating acceptable, defective sample result
◉ Sampling Stringency? How do we increase sampling stringency?. Answer: - improving opportunity to detect pathogen
- reduce likelihood of non-detected pathogen transmission
- reduce likelihood of low quality foods (hard to pass. you want rigor. the harder i am to pass, the better quality that got passed by me) How? INCREASE n DECREASE c ◉ know how to use ISMSF and the 15 "cases" chart***. Answer: ◉ FSO (food safety objective). Answer: Maximum amount of pathogen, toxin allowed in food at time of consumption NOT equal to microbiological criteria
Allows quantifiable food safety goals that processors and retailers can achieve Best carried out using quantitative risk assessment ◉ Using FSOs for Food Safety. Answer: Relay public health goal to industry Food chain and food safety validation Assist development of microbiological criteria for food ingredients ◉ Indicator. Answer: presence INDICATES failure to process a food or ingredient under hygienic conditions (for example: process failure, non-hygienic production, production contamination) (Do not indicate likely pathogen contamination) ◉ index.
Answer: - E. Coli
- Ferment lactose to acid and gas (24 hr @ 44.5C)
- Thermo-tolerant Coliforms
- Can indicate pathogen presence (Salmonella) (but not a strong correlation) ◉ What makes a good Indicator and Index Microbe. Answer: Indicators
- Easily and quickly detected, distinguishable
- Consistently present Index Organisms
- Present when pathogen is present, absent when pathogen is absent
- Numbers of index should correlate
- Inactivation kinetics similar to pathogen
- Growth capacity and requirements should mirror pathogen
- Fecal pathogen index organisms- should be linked to GI ◉ Reportable Diseases. Answer: State law mandates these to be reported to state by local and municipal health authorities
◉ Notifiable Diseases. Answer: States don't have to give this info up- but they voluntarily do (to CDC) ◉ CDC 2016 Gram + Notifiable Diseases (Bacterial). Answer: Botulism Brucellosis Campylobacteriosis Cholera Listeriosis Q-Fever Salmonellosis Shiga toxin-producing E.coli Shigellosis Vibriosis Yersinosis ◉ Foodborne Disease Outbreak. Answer: 2 + persons consuming shared food item within local area/time
