MAP, product safety and nutritional quality 213 Table 11.1 Growth of Yersina enterocolitica in different atmosphere Product pH Temp. Storage Atmosphere Increase Reference typ C time ( days) CO2/N2) Beef O/100/0 0/100/0 3 02040 4 (1989) 1195 Sliced 1.5112 100/00 Hudson et al (1994) 5.57 Bodnaruk and 4 Draughon 6.21 /100/0 2877761 vacuum 0/20/80 Manu- Tawiah et al 10/40/504.0 vacuum 4.1 Lamb 5.4-5.8 Doherty et al. 1995) 0/100/0 80/20/0 0/50/50 0/100/0 vacuum of vacuum packaged fresh products, such as chicken breasts et al, 1996), lamb at 0C under high pH conditions(Doherty 1996), and at-2.C(Gill and Reichel, 1989), and in sliced roast beef at 1.5C (Hudson et aL., 1994). Devlieghere et al.(2000a)developed a model, predicting the influence of temperature and CO2 on the growth of A. hydrophila Proliferation of A. hydrophila is greatly affected by CO2 enriched atmospheres Some reports regarding the effect of CO2 on the growth of A. hydrophila on meat are summarised in Table 11.2 In a study by Berrang et al.(1989b), regarding controlled atmosphere storage of broccoli, cauliflower and asparagus stored at 4C and 15.C, fast proliferation of A. hydrophila was observed at both temperatures, but growth was not significantly affected by gas atmosphere. Garcia-Gimeno et al.(1996)published the survival of A. hydrophila on mixed vegetable salads (lettuce, red cabbage and carrots)
variety of vacuum packaged fresh products, such as chicken breasts at 3ºC (O¨ zbas et al., 1996), lamb at 0ºC under high pH conditions (Doherty et al., 1996), and at ÿ2ºC (Gill and Reichel, 1989), and in sliced roast beef at 1.5ºC (Hudson et al., 1994). Devlieghere et al. (2000a) developed a model, predicting the influence of temperature and CO2 on the growth of A. hydrophila. Proliferation of A. hydrophila is greatly affected by CO2 enriched atmospheres. Some reports regarding the effect of CO2 on the growth of A. hydrophila on meat are summarised in Table 11.2. In a study by Berrang et al. (1989b), regarding controlled atmosphere storage of broccoli, cauliflower and asparagus stored at 4ºC and 15ºC, fast proliferation of A. hydrophila was observed at both temperatures, but growth was not significantly affected by gas atmosphere. Garcia-Gimeno et al. (1996) published the survival of A. hydrophila on mixed vegetable salads (lettuce, red cabbage and carrots) Table 11.1 Growth of Yersina enterocolitica in different atmospheres Product pH Temp. Storage Atmosphere Increase Reference type (ºC) time (%O2/ (log (days) CO2/N2) cfu/g) Beef >6.0 ÿ2 126 0/100/0 0 Gill and 63 vacuum 2.4 Reichel 0 98 0/100/0 0 (1989) 49 vacuum 4.1 2 42 0/100/0 0 35 vacuum 5.1 5 35 0/100/0 1.9 17 vacuum 5.5 10 10 0/100/0 3.4 5 vacuum 4.0 Sliced 6.1 ÿ1.5 112 0/100/0 0 Hudson et al. roast beef 56 vacuum 4.2 (1994) 3 70 0/100/0 3.8 21 vacuum 4.7 Pork 5.57 30 0/100/0 0 Bodnaruk and (normal) 4 25 vacuum 1.7 Draughon 6.21 30 0/100/0 1.7 (1998) (high) 25 vacuum 2.6 Pork 6.0 35 0/20/80 4.1 Manuchops 4 35 0/40/60 4.0 Tawiah et al. 35 10/40/50 4.0 (1993) 35 vacuum 4.1 Lamb 5.4–5.8 0 28 80/20/0 1.2 Doherty et al. 28 0/50/50 3.9 (1995) 28 0/100/0 1.6 28 vacuum 5.9 28 80/20/0 6.8 28 0/50/50 8.5 28 0/100/0 5.6 28 vacuum 8.1 MAP, product safety and nutritional quality 213
214 Novel food packaging techniques Table 11.2 Growth of Aeromonas hydrophila in different atmospheres Temp. Storage Atmosphere Increase Reference type (°) CO,N,) Beef o/100/0 Gill and (1989) 0/100/0 25370 vacuun 0/10003 008 Sliced. 0/10000 roast beef vacuun (1994) O/100/0 Lamb 54-5.8 34000000 Doherty et al 0/5050 1996 0/100/0 44444 555 vacuu Lamb >60 0 80/20/00 Doherty et al 0/50/500 0/100/00 vacuu 8020/04.2 0/100/00 acuum 4.0 packaged under MA (initial 10% of O2-10% CO2, after 48h 0%Ox-18%CO2)and stored at 4oC while at 15C a fast growth was noticed (5 log units in 24h). The combination of high CO2 concentration and low temperature was revealed as responsible for the inhibition of growth. Bennik et al.(1995)concluded from their solid-surface model that at MA-conditions, generally applied for minimally processed vegetables(1-5%O2 and 5-10% CO2), growth of A. hydrophila is possible. Growth was virtually the same under 1.5% and 21%O2. The behaviour of a cocktail of A caviae(HG4)and A bestiarum(hg2)in air or in low O2-low cO2 atmosphere was investigated in fresh-cut vegetables: no difference between both atmospheres was observed on grated carrots, a decreased growth on shredded Belgian endive and Brussels sprouts in Ma but an increased growth on shredded iceberg lettuce in MA storage (Jacxsens et al., 1999)
packaged under MA (initial 10% of O2-10% CO2, after 48h 0% O2-18% CO2) and stored at 4ºC while at 15ºC a fast growth was noticed (5 log units in 24h). The combination of high CO2 concentration and low temperature was revealed as responsible for the inhibition of growth. Bennik et al. (1995) concluded from their solid-surface model that at MA-conditions, generally applied for minimally processed vegetables (1–5% O2 and 5–10% CO2), growth of A. hydrophila is possible. Growth was virtually the same under 1.5% and 21% O2. The behaviour of a cocktail of A. caviae (HG4) and A. bestiarum (HG2) in air or in low O2-low CO2 atmosphere was investigated in fresh-cut vegetables: no difference between both atmospheres was observed on grated carrots, a decreased growth on shredded Belgian endive and Brussels sprouts in MA but an increased growth on shredded iceberg lettuce in MA storage (Jacxsens et al., 1999). Table 11.2 Growth of Aeromonas hydrophila in different atmospheres Product pH Temp. Storage Atmosphere Increase Reference type (ºC) time (%O2/ (log (days) CO2/N2) cfu/g) Beef >6.0 ÿ2 126 0/100/0 0 Gill and 63 vacuum 1.0 Reichel 0 98 0/100/0 0 (1989) 49 vacuum 3.1 2 42 0/100/0 0 35 vacuum 3.0 5 35 0/100/0 0 17 vacuum 3.0 10 10 0/100/0 3.8 5 vacuum 5.8 Sliced 6.1 ÿ1.5 112 0/100/0 0 Hudson et al. roast beef 56 vacuum 4.3 (1994) 3 70 0/100/0 3.1 21 vacuum 4.6 Lamb 5.4–5.8 0 45 80/20/0 0 Doherty et al. 45 0/50/50 0 (1996) 45 0/100/0 0 45 vacuum 0 5 45 80/20/0 0 45 0/50/50 0 45 0/100/0 0 45 vacuum 0 Lamb >6.0 0 42 80/20/0 0 Doherty et al. 42 0/50/50 0 (1996) 42 0/100/0 0 42 vacuum 4.1 5 42 80/20/0 4.2 42 0/50/50 1.7 42 0/100/0 0 42 vacuum 4.0 214 Novel food packaging techniques
AAP, product safety and nutritional quality 215 11. 5 The effect of MAP on the nutritional quality of non respiring food products By using modified atmosphere packaging, the shelf-life of the packaged products can be extended by 50-200%, however, questions could arise regarding the nutritional consequences of MAP on the packaged food products. This section will discuss the effect of MAP on the nutritional quality of non-respiring food products while the effect of MAP on the nutritional value of respiring products, such as fresh fruits and vegetables, will be discussed in detail in the following sections Very little information is available about the influence of MAP on the nutritional quality of non-respiring food products. In most cases, for packaging non-respiring food products, oxygen is excluded from the atmosphere and therefore one should expect a retardation of oxidative degradation reactions Moreover, modified atmosphere packaged food products should be stored under refrigeration to allow CO2 to dissolve and perform its antimicrobial action. At these chilled conditions, chemical degradation reactions have only a limited No information is available regarding the nutritional consequences of enriched oxygen concentrations in modified atmospheres which can be applied for packaging fresh meat and marine fish. Some oxidative reactions can occur with nutritionally important compounds such as vitamins and polyunsaturated fatty acids. However, no quantitative information is available about these degradation reactions in products packaged in O2 enriched atmospheres 11.6 The effect of MAP on the nutritional quality of fresh fruits and vegetables: vitamin C and carotenoids During the last few years many studies have demonstrated that fruit and egetables are rich sources of micronutrients and dietary fibre. They also contain an immense variety of biologically active secondary metabolites that provide the plant with colour, flavour and sometimes antinutritional or toxic properties (Johnson et al., 1994). Among the most important classes of such substances are vitamin C, carotenoids, folates, flavonoids and more complex phenolics aponins, phytosterols, glycoalkaloids and the glucosinolates The nutrient content of fruit and vegetables can be influenced by various factors such as genetic and agronomic factors, maturity and harvesting methods, and postharvest handling procedures. There are some postharvest treatments which undoubtedly improve food quality by inhibiting the action of oxidative enzymes and slowing down deleterious processes. Storage of fresh fruits and vegetables within the optimum range of low O2 and/or elevated CO2 atmospheres for each commodity reduces their respiration and C2H4 production rates(Kader, 1986 Kader, 1997). Optimum CA retards loss of chlorophyll, biosynthesis of carotenoids and anthocyanins, and biosyntheses and oxidation of phenolic compounds
11.5 The effect of MAP on the nutritional quality of nonrespiring food products By using modified atmosphere packaging, the shelf-life of the packaged products can be extended by 50–200%, however, questions could arise regarding the nutritional consequences of MAP on the packaged food products. This section will discuss the effect of MAP on the nutritional quality of non-respiring food products while the effect of MAP on the nutritional value of respiring products, such as fresh fruits and vegetables, will be discussed in detail in the following sections. Very little information is available about the influence of MAP on the nutritional quality of non-respiring food products. In most cases, for packaging non-respiring food products, oxygen is excluded from the atmosphere and therefore one should expect a retardation of oxidative degradation reactions. Moreover, modified atmosphere packaged food products should be stored under refrigeration to allow CO2 to dissolve and perform its antimicrobial action. At these chilled conditions, chemical degradation reactions have only a limited importance. No information is available regarding the nutritional consequences of enriched oxygen concentrations in modified atmospheres which can be applied for packaging fresh meat and marine fish. Some oxidative reactions can occur with nutritionally important compounds such as vitamins and polyunsaturated fatty acids. However, no quantitative information is available about these degradation reactions in products packaged in O2 enriched atmospheres. 11.6 The effect of MAP on the nutritional quality of fresh fruits and vegetables: vitamin C and carotenoids During the last few years many studies have demonstrated that fruit and vegetables are rich sources of micronutrients and dietary fibre. They also contain an immense variety of biologically active secondary metabolites that provide the plant with colour, flavour and sometimes antinutritional or toxic properties (Johnson et al., 1994). Among the most important classes of such substances are vitamin C, carotenoids, folates, flavonoids and more complex phenolics, saponins, phytosterols, glycoalkaloids and the glucosinolates. The nutrient content of fruit and vegetables can be influenced by various factors such as genetic and agronomic factors, maturity and harvesting methods, and postharvest handling procedures. There are some postharvest treatments which undoubtedly improve food quality by inhibiting the action of oxidative enzymes and slowing down deleterious processes. Storage of fresh fruits and vegetables within the optimum range of low O2 and/or elevated CO2 atmospheres for each commodity reduces their respiration and C2H4 production rates (Kader, 1986; Kader, 1997). Optimum CA retards loss of chlorophyll, biosynthesis of carotenoids and anthocyanins, and biosyntheses and oxidation of phenolic compounds. MAP, product safety and nutritional quality 215