Stability of Shredded Mozzarella Cheese Under Modified Atmospheres

Abstract

Stability of Mozzarella cheese was studied under 8 modified atmospheres (air, vacuum and mixtures carbon dioxide/nitrogen) during 8 wk. Samples, packaged in barrier bags and stored at 10ЊC, were periodically evaluated to investigate microbiological quality and composition of headspace gases. Both consumption of oxygen and production of carbon dioxide occurred in many packages. Modified atmospheres containing carbon dioxide efficiently stabilized lactic and mesophilic flora, while inhibiting staphylococci, molds and yeast. Psychrotrophs grew in all samples but were less numerous in high CO 2 atmospheres. Levels of 75% CO 2 were optimal to repress undesirable organisms and reduce gas formation.

Effect of MAP on microbiological quality of Mozzarella cheese stored in different packages at 7 ± 1 °C

“…At the end of 12 weeks, A 3 (100% CO 2 ) showed lower increase in psychrotrophs compared to others revealing that the growth was retarded when the atmosphere inside the package contained higher concentration of CO 2 . Similar results were observed by Eliot et al (1998) that the initial psychrotrophic count (4.4 log cfu/g) of shredded Mozzarella cheese reached 7 log cfu/g after 3 weeks and then stabilized around 7.2 log cfu/g under modified atmosphere. However, these results did not confirm the inhibitory effect of CO 2 on psychrotrophs, which has been demonstrated by Chen and Hotchkiss (1991) and Fedio et al (1994).…”

“…what really inhibited the growth of yeasts was CO 2 . Eliot et al (1998) also confirmed that the growth of Y and M in Mozzarella cheese was inhibited under MAP condition (>50% CO 2 ) upto 8 weeks at 7°C. Storage, two types of packages, interactions of atmospheres × packages and storage × atmospheres significantly (p<0.01) influenced the Y and M counts.…”

Evaluating the effect of modified atmosphere packaging on cheese characteristics: a review

“…Alves et al (1996) demonstrated that MAP (100% CO 2 ) was able to retard just the beginning of the psychrotrophic bacteria growth in Mozzarella cheese, which was confirmed by others (Pintado and Malcata 2000 on Requeijão cheese; Gammariello et al 2009a on Apulian fresh cheeses). Also, Eliot et al (1998) found that there was psychrotroph growth during the first weeks of storage for those with the modified atmospheres under study (10%, 25%, 50%, 75%, 100% N 2 ) since psychrophiles are a complex population and species in Mozzarella cheeses are resistant to CO 2 inhibitory effect. In addition, different storage temperatures (10°C by Moir et al 1993 on Cottage cheese; 7°C by Alves et al 1996 on Mozzarella cheese; 10°C by Eliot et al 1998 on Cameros cheese; 4°C by Gonzalez-Fandos et al 2000 on Cameros cheese) were evaluated as a possible contributor means for MAP in controlling psychrotrophic bacteria growth, and applying low temperatures was found to be a fruitful hurdle in combination with MAP.…”

“…Eliot et al (1998) studied the growth of staphylococci under different MAP conditions (10%, 25%, 50%, 100% CO 2 , and 100% N 2 on Mozzarella cheese). Its growth was inhibited in all studied treatments; the counts of staphylococci were 1 log CFU.g −1 after 8 weeks storage and did not meet the suggested microbial threshold of 10 7 CFU.g −1 (ICMSF 1978).…”

“…CO 2 changes & Remaining constant: The equilibrium between CO 2 dissolution in the cheese mass and CO 2 production through aerobic microbial metabolism (Eliot et al 1998) & Increasing:C O 2 production by the growth of aerobic and anaerobic microorganisms (Alves et al 1996), hetero-fermentative Lactobacilli (Lee et al 1990;Bellengier et al 1993), yeasts activities (Belin 1990), and cheese respiration (Juric et al 2003 and absorption to the EPS tray (Alves et al 1996) and permeability of packaging film to O 2 (Maniar et al 1994) & Decreasing: (1) Aerobic consumption by microorganisms, oxidative and enzymatic reactions involving oxygen (Fedio et al 1994;Eliot et al 1998) and (2) cheese respiration (Juric et al 2003) As far as N 2 is concerned, its concentration inside the package is affected by N 2 penetration into the package when its level becomes <78% and a balanced relationship between N 2 and CO 2 levels [as N 2 =100%_ (% CO 2 +% O 2 )] (Alves et al 1996;Eliot et al 1998).…”