THE EFFECTS OF CHITOSAN COATING CONTAINING DIFFERENT ADDITIVES ON SOME PHYSICAL AND CHEMICAL PROPERTIES OF CHEESE DURING STORAGE

Project no. 29740 · Status: Kapanmış · 2023

Summary

<p class="ql-align-justify"> In&nbsp;this&nbsp;thesis&nbsp;study,&nbsp;active&nbsp;edible&nbsp;coatings&nbsp;were&nbsp;developed&nbsp;by&nbsp;integrating&nbsp;a&nbsp;phenolic&nbsp;extract&nbsp;obtained&nbsp;from&nbsp;hazelnut&nbsp;shells&nbsp;an&nbsp;agricultural&nbsp;waste&nbsp;and&nbsp;industrial&nbsp;byproduct&nbsp;and&nbsp;an&nbsp;essential&nbsp;oil&nbsp;distilled&nbsp;from&nbsp;mountain&nbsp;tea&nbsp;(<em>Sideritis&nbsp;congesta</em>),&nbsp;a&nbsp;medicinal&nbsp;plant,&nbsp;into&nbsp;a&nbsp;chitosan&nbsp;matrix,&nbsp;a&nbsp;natural&nbsp;biopolymer.&nbsp;The&nbsp;developed&nbsp;active&nbsp;coatings&nbsp;were&nbsp;incorporated&nbsp;into&nbsp;the&nbsp;preservation&nbsp;process&nbsp;of&nbsp;İzmir&nbsp;Tulum&nbsp;cheese,&nbsp;one&nbsp;of&nbsp;Turkey's&nbsp;traditional&nbsp;delicacies.</p><p class="ql-align-justify"> In&nbsp;the&nbsp;first&nbsp;phase&nbsp;of&nbsp;the&nbsp;study,&nbsp;active&nbsp;films&nbsp;were&nbsp;produced&nbsp;by&nbsp;adding&nbsp;hazelnut&nbsp;shell&nbsp;extract&nbsp;(2.5%,&nbsp;5%,&nbsp;and&nbsp;10%)&nbsp;and&nbsp;mountain&nbsp;tea&nbsp;essential&nbsp;oil&nbsp;(0.25%,&nbsp;0.50%,&nbsp;and&nbsp;1%)&nbsp;at&nbsp;various&nbsp;concentrations&nbsp;to&nbsp;the&nbsp;prepared&nbsp;2%&nbsp;chitosan&nbsp;film&nbsp;solutions.&nbsp;To&nbsp;determine&nbsp;the&nbsp;optimal&nbsp;addition&nbsp;ratios&nbsp;of&nbsp;these&nbsp;films,&nbsp;detailed&nbsp;film&nbsp;characterization&nbsp;analyses&nbsp;were&nbsp;carried&nbsp;out&nbsp;(thickness,&nbsp;water&nbsp;solubility,&nbsp;CIE&nbsp;<em>Lab</em>*&nbsp;colour,&nbsp;light&nbsp;transmittance&nbsp;and&nbsp;opacity,&nbsp;tensile&nbsp;strength,&nbsp;elongation&nbsp;at&nbsp;break,&nbsp;total&nbsp;phenolic&nbsp;content,&nbsp;DPPH&nbsp;and&nbsp;ABTS&nbsp;antioxidant&nbsp;activity,&nbsp;scanning&nbsp;electron&nbsp;microscopy&nbsp;(SEM),&nbsp;and&nbsp;Fourier-transform&nbsp;infrared&nbsp;spectroscopy&nbsp;(FTIR)).&nbsp;Based&nbsp;on&nbsp;the&nbsp;characterization&nbsp;results,&nbsp;the&nbsp;formulations&nbsp;containing&nbsp;10%&nbsp;hazelnut&nbsp;shell&nbsp;extract&nbsp;and&nbsp;1%&nbsp;mountain&nbsp;tea&nbsp;essential&nbsp;oil,&nbsp;which&nbsp;exhibited&nbsp;the&nbsp;highest&nbsp;bioactive&nbsp;performance&nbsp;and&nbsp;UV-barrier&nbsp;properties,&nbsp;were&nbsp;selected&nbsp;as&nbsp;the&nbsp;optimal&nbsp;coating&nbsp;material.</p><p class="ql-align-justify"> In&nbsp;the&nbsp;second&nbsp;phase&nbsp;of&nbsp;the&nbsp;study,&nbsp;cheese&nbsp;samples&nbsp;were&nbsp;divided&nbsp;into&nbsp;groups&nbsp;control,&nbsp;chitosan&nbsp;alone,&nbsp;chitosan&nbsp;with&nbsp;an&nbsp;optimal&nbsp;amount&nbsp;of&nbsp;hazelnut&nbsp;shell&nbsp;extract,&nbsp;chitosan&nbsp;with&nbsp;an&nbsp;optimal&nbsp;amount&nbsp;of&nbsp;mountain&nbsp;tea&nbsp;essential&nbsp;oil,&nbsp;and&nbsp;chitosan-coated&nbsp;vacuum-packaged&nbsp;samples&nbsp;and&nbsp;stored&nbsp;under&nbsp;refrigerated&nbsp;conditions&nbsp;(+4&nbsp;°C)&nbsp;for&nbsp;90&nbsp;days.&nbsp;Changes&nbsp;occurring&nbsp;in&nbsp;the&nbsp;physicochemical,&nbsp;microbiological,&nbsp;textural,&nbsp;and&nbsp;sensory&nbsp;properties&nbsp;of&nbsp;the&nbsp;samples&nbsp;were&nbsp;examined&nbsp;during&nbsp;the&nbsp;storage&nbsp;period.</p><p class="ql-align-justify"> As&nbsp;a&nbsp;result&nbsp;of&nbsp;the&nbsp;study,&nbsp;it&nbsp;was&nbsp;determined&nbsp;that&nbsp;the&nbsp;chitosan-based&nbsp;edible&nbsp;coatings&nbsp;and&nbsp;vacuum&nbsp;packaging&nbsp;formed&nbsp;an&nbsp;effective&nbsp;moisture&nbsp;barrier&nbsp;on&nbsp;the&nbsp;cheese&nbsp;surface,&nbsp;minimizing&nbsp;weight&nbsp;loss&nbsp;and&nbsp;successfully&nbsp;preserving&nbsp;the&nbsp;cheese's&nbsp;characteristic&nbsp;colour&nbsp;stability&nbsp;and&nbsp;structural&nbsp;integrity&nbsp;against&nbsp;enzymatic&nbsp;weakening.&nbsp;Owing&nbsp;to&nbsp;the&nbsp;strong&nbsp;antimicrobial&nbsp;and&nbsp;antioxidant&nbsp;barrier&nbsp;properties&nbsp;exhibited&nbsp;by&nbsp;the&nbsp;chitosan&nbsp;coatings&nbsp;containing&nbsp;extract&nbsp;and&nbsp;essential&nbsp;oil,&nbsp;microbial&nbsp;growth&nbsp;on&nbsp;the&nbsp;cheese&nbsp;surface&nbsp;was&nbsp;brought&nbsp;under&nbsp;control;&nbsp;accordingly,&nbsp;proteolytic&nbsp;and&nbsp;lipolytic&nbsp;enzyme&nbsp;activities&nbsp;were&nbsp;slowed,&nbsp;limiting&nbsp;the&nbsp;accumulation&nbsp;of&nbsp;free&nbsp;amino&nbsp;acids&nbsp;and&nbsp;free&nbsp;fatty&nbsp;acids&nbsp;in&nbsp;the&nbsp;cheese&nbsp;matrix.</p><p class="ql-align-justify"> The&nbsp;accumulation&nbsp;of&nbsp;biogenic&nbsp;amines,&nbsp;which&nbsp;pose&nbsp;a&nbsp;threat&nbsp;to&nbsp;human&nbsp;health,&nbsp;varied&nbsp;depending&nbsp;on&nbsp;the&nbsp;initial&nbsp;salt&nbsp;concentration&nbsp;and&nbsp;packaging&nbsp;method&nbsp;of&nbsp;the&nbsp;cheese,&nbsp;in&nbsp;parallel&nbsp;with&nbsp;microbial&nbsp;growth&nbsp;and&nbsp;proteolytic&nbsp;activity.&nbsp;In&nbsp;the&nbsp;salted&nbsp;control&nbsp;group&nbsp;without&nbsp;a&nbsp;protective&nbsp;coating,&nbsp;the&nbsp;osmotic&nbsp;stress&nbsp;created&nbsp;by&nbsp;high&nbsp;salinity&nbsp;accelerated&nbsp;free&nbsp;amino&nbsp;acid&nbsp;accumulation;&nbsp;it&nbsp;exceeded&nbsp;the&nbsp;toxicity&nbsp;limit&nbsp;(900&nbsp;mg/kg)&nbsp;at&nbsp;903.76&nbsp;mg/kg&nbsp;on&nbsp;day&nbsp;60&nbsp;and&nbsp;reached&nbsp;1229.72&nbsp;mg/kg&nbsp;on&nbsp;day&nbsp;90,&nbsp;thereby&nbsp;losing&nbsp;product&nbsp;safety.&nbsp;In&nbsp;the&nbsp;salted&nbsp;cheeses&nbsp;with&nbsp;active&nbsp;coating&nbsp;and&nbsp;vacuum&nbsp;application&nbsp;at&nbsp;the&nbsp;same&nbsp;salinity,&nbsp;the&nbsp;excessive&nbsp;increase&nbsp;was&nbsp;prevented,&nbsp;and&nbsp;the&nbsp;biogenic&nbsp;amine&nbsp;content&nbsp;remained&nbsp;within&nbsp;the&nbsp;range&nbsp;of&nbsp;600.41-835.10&nbsp;mg/kg&nbsp;on&nbsp;day&nbsp;90.&nbsp;In&nbsp;the&nbsp;uncoated&nbsp;low-salt&nbsp;control&nbsp;group,&nbsp;on&nbsp;the&nbsp;other&nbsp;hand,&nbsp;as&nbsp;the&nbsp;osmotic&nbsp;stress&nbsp;eased,&nbsp;decarboxylase&nbsp;activity&nbsp;decreased,&nbsp;remaining&nbsp;lower&nbsp;than&nbsp;the&nbsp;salted&nbsp;control&nbsp;at&nbsp;598.92&nbsp;mg/kg&nbsp;on&nbsp;day&nbsp;90.&nbsp;In&nbsp;the&nbsp;low-salt&nbsp;coated&nbsp;groups,&nbsp;in&nbsp;which&nbsp;decarboxylation&nbsp;was&nbsp;suppressed,&nbsp;a&nbsp;total&nbsp;biogenic&nbsp;amine&nbsp;content&nbsp;of&nbsp;290.44-404.90&nbsp;mg/kg&nbsp;was&nbsp;determined&nbsp;on&nbsp;day&nbsp;90.</p><p class="ql-align-justify"> Sensory&nbsp;analysis&nbsp;evaluations&nbsp;revealed&nbsp;that&nbsp;the&nbsp;cheese&nbsp;retained&nbsp;its&nbsp;distinctive&nbsp;sensory&nbsp;profile&nbsp;and&nbsp;received&nbsp;high&nbsp;overall&nbsp;acceptance&nbsp;scores&nbsp;from&nbsp;the&nbsp;panellists.&nbsp;In&nbsp;conclusion,&nbsp;upon&nbsp;evaluation&nbsp;of&nbsp;all&nbsp;analytical&nbsp;data,&nbsp;it&nbsp;was&nbsp;determined&nbsp;that&nbsp;the&nbsp;combinations&nbsp;of&nbsp;chitosan&nbsp;coatings&nbsp;enriched&nbsp;with&nbsp;hazelnut&nbsp;shell&nbsp;extract&nbsp;and&nbsp;mountain&nbsp;tea&nbsp;essential&nbsp;oil&nbsp;together&nbsp;with&nbsp;vacuum&nbsp;packaging&nbsp;reduced&nbsp;quality&nbsp;losses&nbsp;in&nbsp;the&nbsp;cheeses,&nbsp;prevented&nbsp;toxicological&nbsp;health&nbsp;risks,&nbsp;and&nbsp;significantly&nbsp;preserved&nbsp;storage&nbsp;stability.</p><p class="ql-align-justify"><strong>Keywords:</strong>&nbsp;Chitosan,&nbsp;active&nbsp;packaging,&nbsp;Izmir&nbsp;Tulum&nbsp;cheese,&nbsp;hazelnut&nbsp;shell&nbsp;extract,&nbsp;mountain&nbsp;tea&nbsp;essential&nbsp;oil,&nbsp;biogene&nbsp;amine.</p><p></p>

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