freshness indicators in food processing & preservation
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The document discusses the importance of freshness indicators in food packaging, focusing on how they monitor food quality and spoilage through various chemical and biochemical processes. It outlines different types of freshness indicators, including visible and invisible options, and highlights innovations like biosensors and electronic noses that aid in tracking the freshness of food products. Additionally, it emphasizes the challenges and future prospects for implementing these technologies in the food industry.
freshness indicators in food processing & preservation
- 1. FRESHNESS INDICATORS in FOOD PACKAGING Presentaion By B.L.Prasanna PG/FT/0088118
- 2. INTRODUCTION Consumers are more and more looking for "freshness" but this property is not guaranteed enough by directions required by the law, such as the "best before date" or the "use by date“. The loss of quality of foods is related to a combination of processes of different nature, specific for each product that can be chemical, biochemical, physical, or physico- chemical
- 3. Chemical Reactions and Physical Processes Altering Food Quality CHEMICAL AND BIOCHEMICAL REACTIONS PHYSICAL OR PHYSICAL- CHEMICAL PROCESSES Non enzymatic browning Enzymatic browning Hydrolisis of lipids Oxidation of lipids Hydrolisis of proteins Denaturation of proteins Aggregation of proteins Hydrolysis of polysaccharides Glycolysis Polysaccharides synthesis Discoloration of natural pigments Inactivation of vitamins Changes in bio-availability of vitamins and minerals Recrystallization of sugars Starch retrogradation Loss of aroma Sorption/Desorption of water Loss of compartmentalization
- 4. What is Freshness indicator? Measures the quality - life cycle. Spoilage Or lack of freshness. Communicate the quality The freshness depends - 2 factors:- Degree of freshness Lack of spoilage
- 5. Freshness Indicator Functions Monitor – quality Track -through the critical points in the supply chain. Check the condition - anywhere along the supply chain. Measure directly the level of (microbiological) contamination Reduce - consumer complaints.
- 8. DEVOLOPMENT – FRESHNESS INDICATORS! We require the knowledge on • Quality indicating metabolites in the food already present Metabolites produced by the micro- organism Concentration of the metabolites
- 9. Compounds IndicatingThe Quality PackedFood Product GLUCOSE (glucose gradient) ORGANIC ACIDS (L-lactic to D, in case meat) ETHANOL (eth conc.-viable count of microbes- fish) VOLATILE NITROGEN COMPOUNDS (trimethylamine, ammonia-fish) BIOGENIC AMINES( putrecine & histamine in fish–hygiene indicator to an extent) CARBON DIOXIDE ATP Degradation Compounds (K-value) H2S AND SULPHURIC COMPOUNDS( spoilage of poultry by Psedo..,Altromonas, results these..) Ferm entati on
- 10. There are mainly 2 types of freshness indicators Visible indicators - distinguishable and interpretable by consumers, "quality labels" - guarantee premium quality Invisible indicators- Invisible to the consumer, integrate a (RFID) tag that can be read automatically at a distance, both during distribution and in retail stores. TYPES OF FRESHNESS INDICATORS
- 13. Indicators sensitive to pH change Change colour - presence of volatile compounds Direct determination of CO2 – pH dye (eg.Fuchsine acid) Use of the pH-dye bromothymol blue -indicator - formation of CO2 - microbial growth
- 14. • Increase in CO2 - determine by microbial contamination - CO2-sensitive packaging indicator • Ripeness of traditional fermented vegetable foods • Most frequently used pH-dye bromothymol blue, many other reagents e.g. xylenol blue, bromocresol purple, bromocresol green, cresol red, phenol red, methyl red and alizarin Contd…
- 15. RipeSense(r) indicator currently being trialled in New Zealand and the USA. Triggered by the aroma components excreted by the fruits.
- 16. Label indicator of fruit maturation level
- 17. Indicators sensitive to volatile nitrogen compounds A plastic chip incorporating a reagent-containing wick. Label - attached to the package the sharp barb on the back - penetrated - enables contact between the package headspace gases and the reagent. As volatile amines passed - a bright pink colour - along the wick.
- 18. Fresh Tag
- 19. Indicators sensitive to hydrogen sulphide Colour change of myoglobin by hydrogen sulphide (H2S) - during the ageing - packaged poultry. Commercially - prepared myoglobin dissolved in a sodium phosphate buffer on small squares of agarose.
- 20. Fresh-Q Freshness of packaged meat. FreshQ, is a stick-on freshness sensor - outside of fresh wrapped meat and poultry packages. Detect food-borne bacteriological levels right through the wrap. A tangerine orange color - fresh. When the bacteria count se’s to a critical level ORANGE -> GRAY
- 21. Fresh-Q label
- 22. Nano sensors Nanolayer of silver reacts with hydrogen sulphide and forms silver sulphide A visually detectable colour change from opaque light brown to transparent
- 23. Indicators sensitive to miscellaneous microbial metabolites Detecting the unacceptability -Respiring products by measuring ethanol - headspace with the aid of alcohol oxidase, peroxidase and a chromogenic substrate. Diacetyl is a volatile compound evolving from meat as spoilage takes place A diamine dye-based sensor system - presence of diacetyl vapour. Diacetyl migrating through the packaging material would react with the dye and induce a colour change.
- 24. Timestrip® smart labels Timestrip® is more accurate than human assumptions Some Potential use’s Useful for food items at high risk to bacteria growth Monitor freshness Track food freshness in transit and storage They can be applied to food items where there is a high risk of bacteria They are easy to apply and use
- 25. Applications Fresh fish & Meat Fruit and vegetables – monitor freshness and help with the first in-first out principle Poultry – bacteria can be found on raw or undercooked chicken that multiplies rapidly at temperatures between 40 °F and 140 °F (can occur out of refrigeration and before thorough cooking occurs) Condiments - e.g. mayonaisse, salad cream, chutney, mustard, tomato sauce or brown sauce all have use within dates while a dynamic date can ensure these are used at their best and reduce waste
- 26. Pathogen indicators Commercially - Toxin GuardTM polyethylene-based packaging material - able to detect the presence of pathogenic bacteria is in contact with the material Bound first to a specific, labelled antibody and then to a capturing antibody printed as a certain pattern Detection of pesticide residues or proteins resulting from genetic modifications. Detection of specific microorganisms like Salmonella sp., Listeria sp. and E. coli is Food Sentinel SystemTM.
- 27. Toxin indicators Toxin Indicators detect microbial growth or toxins produced by pathogenic microorganisms
- 28. ToxinGuard
- 29. Cont… Based on immunochemical reaction, the reaction taking place in a bar code. If the particular microorganism is present the bar code is converted unreadable. Composed of cross-polymerised polydiacetylene molecules and has a deep blue colour. The toxin binds - polydiacetylene film, the colour of the film changes from blue to red.
- 30. Contamination detection Placing antibody-based tests on polymer packaging films to detect pathogens or other selected micro organisms. The insert sends a visual alert when it encounters targeted spoilage bacteria, or pathogens such as E-coli, Listeria and Salmonella. It will also alert consumers if chemicals such as those used for pesticides are present in a food.
- 31. Freshness indicators Label is transparent: product is fresh Label is red & bar code is veiled product is spoiled
- 33. RFID Wireless monitoring of food packages through tags, readers, and computer systems. RFID systems provide safety and security benefits by tracking the origin of food supplies. Computer Reader RFID tag
- 34. RFID Advantages - Better logistics for retailers – Better product info – Improved shopping experience – Safety, traceability Disadvantages – Cost – Technology not yet mature – Physical limitations – No industrystandard
- 35. What is Biosensors? Compact analytical devices that detect, record and transmit information pertaining to biological reactions
- 36. Why Biosensors? Bioreceptor specific to a target analyte (enzymes, antigens, microbes, hormones etc.) Transducer to convert biological signals to an electrical response (electrochemical, optical etc Specificity Speed/Response time Simplicity Continuous Monitoring Preciseness
- 37. Few commercially available systems, Contaminating bacteria render bar-code unreadable
- 38. Applications in the field of food technology Amprometric biosensor for polyphenolic flavoring compounds in red wines. Electrochemical biosensor –contaminants & flavoring compounds in the food product. Amp. Hypoxanthine bio…fish & meat tissue off odors In wine industry, these sensors are being developed to analyze the sugar to alcohol ratio in grapes and specific flavor from the wine
- 39. ELECTRONIC NOSES Electronic nose is a analytical tool composed of array of sensors i.e. metal oxide or polymer. Capable of responding to volatile compounds with changes in there electrical properties. In this single compound is not analyzed but samples are classified as acceptable or unacceptable.
- 40. MECHANISM-ELECTRONICNOSE SAMPLE/ VAP Control ler & algorit hm with in (compu ter) SENSOR - 1 SENSOR- 2 SENSOR- 3 SENSOR- 4 V A P RESPONSE DATA RESPONSE SIGNALS RESPONSE DATA RESPONSE SIGNALS TR AN SD UC ER MEA SURE ABLE SIGN AL
- 41. SensorfreshQ™ Easily confirms the freshness of uncooked meat or poultry Revolutionary, affordable, portable, handheld electronic “nose”. Quickly measure the bacteriological activity in uncooked meat or poultry. (< 1 min.)
- 42. Procedure In 3 simple steps, 1. Hold and select the meat setting or poultry setting 2. Hold and press the button • A built-in fan draws in the sample atmosphere passed through four electronic sensors that measure by-products of food-borne bacteria 3. Again, Hold and press the button one more time
- 43. Result GREEN LIGHT - fresh YELLOW - ok but eat within 2 days RED - freshness - no longer assured Uses complex algorithms to determine the freshness level
- 44. APPLICATION OF E- NOSES Flavors Aroma Chemically volatile compounds Any complex mixture of volatile compounds Application to dairy products:- - Ageing of milk & self life prediction. - classification of bacteria culture in the milk culture - Determined the rind taste & ripening in the cheese
- 45. Disadvantages of Freshness indicator Based in broad-spectrum color changes Target metabolites do not necessarily indicate ,poor quality
- 46. Future prospects Although research is ongoing in the area of intelligent packaging, the application of these systems in Europe has been limited to a few time-temperature indicators. In addition to information on product identification, date of manufacture, price, etc., new electronic and optical tags could also function as combined time- temperature, leak and/or freshness indicators
- 47. The challenge is to develop an effective sensor that is reliably sensitive to the quality/safety level of a specific food type. Different food quality indicators are being studied by TNO Nutrition and Food Research
- 48. Conclusions Freshness indicators ,Bio-sensors, Electronic noses, Toxin guards (Pathogenic indicators)and other selective indicators are used to detect a number of analyts in food technology as glucose, alcohol ,amino-acids, proteins, bacteria, antioxidants activity ,pH & temperature monitoring etc. Today ,Food industries using these indicators & biosensors but in limited quantities due to high cost ,denaturation problem ,due to bio based material used for there fabrication, We need knowledge of different sciences for its production & better fabrication and even cost effectiveness2
- 49. THANK YOU
- 53. Roast chickent Monoprix benefits fromFresh-Checkindicators from Temptime Corp
Editor's Notes
- #37: 36