Abdul Rahman, Russly

Ibrahim, Roshita

Osman, Azizah

Saari, Nazamid

Universiti Putra Malaysia Institutional Repository

Applied Sciences and TechnologiesStorage Stability of Chilled Minimally Processed Shredded CabbageAzlzah 06man. Nazamld Saari. RU661y Abdul Rahman, Roohlta IbrahimFacultyof Food Science and BiotechnologyUniversiti Putra Malaysia43400 UPM, Serdang, SelangorMalaysiaTelephone Number of Corresponding Author: 03-89468373/8387E-mail olCorrespondingAuthor:azosman@Putra.upm.edu.myKey words: minimally processed cabbage, quality management, packaging, anti- browning agents, low temperaturestorageIntroductionThe availability of certain foods and the consumer's purchasing power has changed the patterns offood consumption. Today,the emphasis has changed from ensuring an adequate supply of calories and nutrients to an increased emphasis on quality andconvenience. This is due to the upgraded living standard and also a great expansion in the food service industries. Thus, thechange in lifestyle has increased the demand of convenience and fresh (or fresh-like) products, which led to a relatively newarea of food preservation, that is, minimally processed foods. By definition, minimally processing (MP) would encompass anyprocedure, short of the traditional complete preservation procedures(heat sterilization, freezing, etc.), that add value. Chilled minimally processed vegetables are vegetables that are washed, cut,peeled, sliced, diced, chopped, shredded followed by low temperature storage to prolong quality retention. Minimallyprocessed vegetables that are now being produced include packaged shredded cabbage, lettuce, carrot, cut chilies, capsicum,peeled and sliced potatoes, sweet potatoes, etc. The shelf-life extension of these fresh cut vegetables is therefore relevantbecause of its economic impact. Packaging can be one of the important factors in determining the storage stability and qualityofthese fresh-cut vegetables. The shelf- life of these minimally processed vegetables is often limited by enzymatic browning,loss in texture (firmness) and moisture content. Whilst their organoleptic properties are strongly altered by the appearance ofbrown pigments. This study was conducted to determine the optimum minimally processing and storage conditions for shelf-life extension of shredded cabbage.Materials and MethodsFreshly picked round white cabbage tBrasstca oleracea L. Capitata) of hybrid KKY - Cross was purchased fromMARDITECH Plantation in Cameron Highlands. A study was conducted to determine the effects of using different types ofpolymeric films (Polypropylene (PP), Low density Polyethylene (LOPE), High density Polyethylene (HOPE) and polyvinylchloride (PVC) cling wrap (Control» of varying permeabilities to gases and water vapour and also with and without theapplication of vacuum packaging on the physico-chemical, biochemical, microbiological characteristics and sensory aspects ofthe minimally processed (MP) shredded cabbage during storage at 5±1 QC;90-95%RH. Studies on the effects of dipping into 4different anti-browning solutions namely 1% ascorbic acid, 0.1% sodium metabisulfite, 0.5%L-cysteine + 0.1% citric acid and0.1% acetic acid on the storage stability otshredded cabbage were also carried out. Sample dipped in distilled water was usedas a control. Changes in physico-chemical characteristics were determined by quantitative measurements of weight loss,colour, texture, ascorbic acid content, pH, titratable acidity, total soluble solid, chlorophyll content, polyphenoloxidase(PPO)activity and degree of browning. Carbon dioxide and ethylene production in the package atmosphere during storage were alsodetermined with gas chromatography. The microbial characteristics determined were mesophilic and psychrotrophic bacterialmold and yeast counts. Sensory evaluation involved subjective acceptability and descriptive analyses. Data collected wereanalyzed using ANOVA and Duncan MUltiple Range test (OMRT) at 5% significant level.Results and DiscussionGenerally, in almost all the analyses done, the quality ofthe chiIled minimally processed shredded cabbage deteriorated withincrease in storage time. Among all the packaging films used, it was found that polypropylene which is the least permeablefilm for gases and water vapour, could extend the shelflife of the minimally processed shredded cabbage almost up to 3 weekswhen stored at 5 ± 1°C; 90-95% relative humidity with minimum colour change, reduction in ascorbic acid content anddeterioration in sensory properties and marginally low changes in other parameters tested. Whilst polyvinyl chloride clingwrap (control) was found to be the least effective packaging film. Different packaging systems did not affect the microtlora ofthe shredded cabbage which was predominantly bacteria, small numbers of yeasts and only an occasional mold for bothmesophilic and psychrotrophic microorganisms. Sample packed in vacuum packaging showed no significant difference withthose in non- vacuum packaging in almost all the parameters tested for all the different packaging films, even though the airfrom the package headspace which can cause oxidation spoilage to the produce had been removed. Anti- browning treatmentof 0.1% sodium metabisulphite gave the best sensory properties and visual colour retention followed by O. I% acetic acidsolution. However, 0.5% L-cysteine + 0.1% citric acid and 1% ascorbic acid solutions were found not to be a very good anti-browning agents for chilled minimally processed shredded cabbage as they gave worse results as compared to the controlsamples.361UPM Research Report 1997-2000. Vol II.Section 2-E?dended AbstractsConclusionsResults obtained in the present study, showed that chilled minimally processed shredded cabbage packed in polypropylenebags ofO.03 mm thickness with permeability characteristics of; Water vapour transmission rate = 5.89 glm2/day; Oxygentransmission rate = >2,000 cc/m2/day; Carbon dioxide transmission rate = 11,931 cc/m2/day, could be stored in good andacceptable condition for a period of almost 3 weeks at 5 ± 1°C; 90-95% relative humidity with a minimum 0.14%physiological loss in weight, minimum loss in other physico-chemical and biochemical characteristics as well as sensoryattributes and staying microbially safe. Meanwhile shredded cabbage in control film (polyvinyl chloride cling wrap) suffered asevere loss of quality after a few days in a similar storage environment. Chilled minimally processed shredded cabbage treatedwith anti-browning solution containing 0.1% sodium metabisulphite gave the best anti - browning effects in terms of retainingcolour and other sensory qualities followed by 0.1% acetic acid solution. Whereas, I% ascorbic acid and the combination of0.5% L-cysteine + 0.1% citric acid were found not to be good anti-browning solutions for minimally processed shreddedcabbage.Benefits from the studyMinimally processing generally increases the rates of metabolic processes that caused deterioration offresh produce. Thephysical damage or wounding caused by preparation increases respiration and ethylene production and other biochemicalreactions responsible for changes in colour (browning), flavour, texture and nutritional quality. The greater the degree ofprocessing, the greater would be the wounding response. Results obtained in this study indicate that chilled minimallyprocessed shredded cabbage packed in polypropylene film could be stored in good and acceptable condition for almost 3weeks. Chilled minimally processed cabbage treated with 0.1% sodium metabisulphite was effective in retaining colour andother sensory qualities followed by 0.1% acetic acid solution. These findings will benefit the expanding production ofminimally processed vegetables, in particular, cabbage, for fresh consumption (production of coleslaw and vegetables salads)in the food service industries and the various fast food outlets in Malaysia.Patent(s), if applicable:NilStage of Commercialization, if applicable:Nil-Project Publications in Refereed Journals:NilProject Publications in Conference Proceedinqs1.00man, A., Saari, N., Abdul Rahman,R. and Ibrahim, R. (2001). Effect of different packaging films on the physico-chemical characteristicsof minimallyprocessed shredded cabbage stored at chilled temperature. In: Proceedingof the MalaysianScience and Technology Congress2001; p 734-742.2.Osman, A., Saari, N., Abdul Rahman,R. and Ibrahim R. (2e02). Effectsof different packaging filmson the degree of browning andchlorophyll degradation of cabbage stored at chilled temperature. To be In :Transaction of the MalaysianSociety of Plant Physiology II,(2002); p xxx.3.0sman, A., Saari. N., Abdul RahmanR. and Ibrahim,R. (2001). Effects of vacuumpackaging on the physico-chemicalcharacteristics ofshredded cabbage stored at chilled temperature. In: 26'" Annual Conference of the MalaysianSociety for Biochemistryand MolecularBiology,Bookof Abstracts (200I); p 40.Graduate ResearchName of Graduate Research TopicRoshita Ibrahim Storage Stability ofChilled MinimallyProcessed ShreddedCabbageField of ExpertisePostharvestTechnologyDegree AwardedMSc.Graduation Year2003IRPA Project number: 01-02-04-0519Project Leader Assoc. Prof. Dr Azizah OsmanUPM Research Cluster: AFF362

Storage stability of chilled minimally processed shredded cabbage

http://psasir.upm.edu.my/42643/1/storage%20stability%20of%20chilled.pdf

Storage stability of chilled minimally processed shredded cabbage

Abstract

Similar works

Full text

Available Versions

Universiti Putra Malaysia Institutional Repository