Table 21.1 Commercial pressurised food products in Japan, Europe and the United States in the last ten years(after Cheftel, 1997) Company Product P/T/time combination Role of hp JAPAN Meidi-ya Fruit based products(pH 4.5); jams 400MPa, 10-30min, Pasteurisation, improved gelation, faster sugar 3 (apple, kiwi, strawberry): jellies 20°C penetration; limiting residual purees; yoghurts: sauces pectinmethylesterase activity Pokka Corp(stopped Grapefruit juice 200 MPa 10-15min. Reduced bittern 5°C Wakayama Food Ind Mandarin juice(winter season only) 300-400 MPa, 2-3 Reduced odor of dimethyl sulphide; reduced (only≈20% of HP juice in final juice20°C thermal degradation of methyl methionine sulphoxide: replace hrst thermal pasteurisation 2 before packing: 90C, 3 Nisshin fine foods Sugar impregnated tropical fruits(kept 50-200MPa Faster sugar penetration and water removal at-18C without freezing). For sorbet and ice cream Fuji chiku mutterham Raw pork ham 250MPa. 3 hours Faster maturation (reduced from 2 weeks to 3 hours); faster tenderisation by internal proteases, improved water retention and shelf Kibun(stopped in Shiokara and raw scallops Microbial sanitation. tenderisation. control autolysis by endogenous proteases Yaizu fisheries(test Fish sausages, terrines and 'pudding 400 MPa Gelation, microbial sanitation, good texture of raw hP gel Raw’sake( rice wine Yeast inactivation, fermentation stopped without heating
438 The nutrition handbook for food processors Table 21.1 Commercial pressurised food products in Japan, Europe and the United States in the last ten years (after Cheftel, 1997) Company Product P/T/time combination Role of HP JAPAN Meidi-ya Fruit based products (pH < 4.5); jams 400 MPa, 10–30 min, Pasteurisation, improved gelation, faster sugar (apple, kiwi, strawberry); jellies; 20 °C penetration; limiting residual purées; yoghurts; sauces pectinmethylesterase activity Pokka Corp. (stopped Grapefruit juice 200 MPa, 10–15 min, Reduced bitterness c2000–2001) 5 °C Wakayama Food Ind. Mandarin juice (winter season only) 300–400 MPa, 2–3 min, Reduced odor of dimethyl sulphide; reduced (only 20% of HP juice in final juice 20 °C thermal degradation of methyl methionine mix) sulphoxide; replace first thermal pasteurisation (after juice extraction) and final pasteurisation before packing: 90 °C, 3 min Nisshin fine foods Sugar impregnated tropical fruits (kept 50–200 MPa Faster sugar penetration and water removal at -18 °C without freezing). For sorbet and ice cream Fuji chiku mutterham Raw pork ham 250 MPa, 3 hours, Faster maturation (reduced from 2 weeks to 20 °C 3 hours); faster tenderisation by internal proteases, improved water retention and shelf life Kibun (stopped in ‘Shiokara’ and raw scallops / Microbial sanitation, tenderisation, control of 1995) autolysis by endogenous proteases Yaizu fisheries (test Fish sausages, terrines and ‘pudding’ 400 MPa Gelation, microbial sanitation, good texture of market only) raw HP gel Chiyonosono ‘Raw’ sake (rice wine) / Yeast inactivation, fermentation stopped without heating
Table 21.1 Commercial pressurised food products in Japan, Europe and the United States in the last ten years(after Cheftel, 1997) Company Product P/T/time combination Role of HP Ice nucleating bacteria(for fruit juice Inactivation of Xanthomonas. no loss of ice and milk) Japanese mandarin juice Echigo seika Moci rice cake, Yomogi fresh aromatic 400-600 MPa, 10min, Microbial reduction, fresh flavour and taste, erbs, hypoallergenic precooked rice 45or70° enhances rice porosity and salt extraction of convenience packs of boiled rice Takansi Fruit juice Pon(test mar Orange juice EUROPE pry(france) Fruit juice(orange, grape fruit, citrus, 400MPa, room Inactivation of micro flora(up to 10CFU/g) mixed fruit juice) temperature partial inactivation of pectinmethylesterase Espuna(Spain) Deli-style processed meats(ham) 400-500 MPa, few ninutes room temperature Orchard house Squeezed orange juice 500MPa. room Inactivation of micro flora(especially yea Ltd. ( UK)(since temperature and enzyme, keeping natt 2001) THE UNITED STATES Avocado paste(guacamole, chipotle 700 MPa, 10-15 min, Micro m inactivation, polyphenoloxidase sauce, salsa) and pieces 20°C nactivation, chilled process Nisbet 300-400MPa, roor Microorganism inactivation, keeping raw taste loey Oyster temperature, 10 m and flavour, no change in shape and size E080≌= ternational Foods indicates no detailed information available
High pressure processing 439 QP corp Ice nucleating bacteria (for fruit juice / Inactivation of Xanthomonas, no loss of ice and milk) nucleating properties Ehime co. Japanese mandarin juice / Cold pasteurisation Echigo seika Moci rice cake, Yomogi fresh aromatic 400–600 MPa, 10 min, Microbial reduction, fresh flavour and taste, herbs, hypoallergenic precooked rice, 45 or 70°C enhances rice porosity and salt extraction of convenience packs of boiled rice allergenic proteins Takansi Fruit juice / Cold pasteurisation Pon (test market in Orange juice / / 2000) EUROPE Pampryl (France) Fruit juice (orange, grape fruit, citrus, 400 MPa, room Inactivation of micro flora (up to 106CFU/g), mixed fruit juice) temperature partial inactivation of pectinmethylesterase Espuna (Spain) Deli-style processed meats (ham) 400–500 MPa, few / minutes, room temperature Orchard House Foods Squeezed orange juice 500 MPa, room Inactivation of micro flora (especially yeast) Ltd. (UK) (since July temperature and enzyme, keeping natural taste 2001) THE UNITED STATES Avomex Avocado paste (guacamole, chipotle 700 MPa, 10–15 min, Microorganism inactivation, polyphenoloxidase sauce, salsa) and pieces 20°C inactivation, chilled process Motivatit, Nisbet Oysters 300–400 MPa, room Microorganism inactivation, keeping raw taste Oyster Co, Joey Oyster temperature, 10 minutes and flavour, no change in shape and size Hannah International Hummus / / Foods / indicates no detailed information available. Table 21.1 Commercial pressurised food products in Japan, Europe and the United States in the last ten years (after Cheftel, 1997) Company Product P/T/time combination Role of HP Continued
440 The nutrition handbook for food processors different influence on the stability of vitamin C during storage. The ascorbic acid content in untreated and pressurised (400 MPa/room temperature/15 min) guava puree started to decline respectively after 10 and 20 days whereas that in heated (88-90C/24s)and( 600 MPa/room temperature/15 min) pressurised guava puree remained constant during 30 and 40 days respectively (Yen and Lin, 1996) Kinetics of vitamin C degradation during storage have been studied in high pressure treated strawberry coulis. Vitamin C degradation of pressurised (400 MPa/20oC/30 min) and untreated coulis are nearly identical during storage at 4C. Moreover, it has been shown that a pressure treatment neither accelerates nor slows down the kinetic degradation of ascorbic acid during subsequent storage(Sancho et al, 1999) The effect of oxygen on ascorbic acid stability under pressure has been studied by Taoukis and co-workers(1998). At 600 MPa and 75C for 40 min exposed to air, ascorbic acid in buffer solution(sodium acetate buffer(0. 1 M: pH 3.5-4)) degraded to 45%o of its initial content while in the absence of oxygen, less vitamin loss was observed. Moreover, the addition of 10% sucrose resulted in a protec tive effect on ascorbic acid degradation. It was also noted that vitamin C loss was higher in fruit juice compared to that in buffer solutions. Vitamin C loss in pine- apple and grapefruit juice after pressurisation(up to 600 MPa and 75C)was max 70%o and 50% respectively. At constant pressure(600 MPa after 40 min), the pres- sure degradation of vitamin C in pineapple juice was temperature sensitive, e.g loss 20-25% at 40C. 45-50% at 60C and 60-70% at 75C in contrast to that in grapefruit juice. Detailed kinetics of combined pressure and temperature stability of ascorbic acid in different buffer(pH 4, 7 and 8)systems and real products(squeezed orange and tomato juices) have been carried out by Van den Broeck and co- workers(1998). At 850MPa and 50C for 1 hour, no ascorbic acid loss was observed. The high pressure/thermal degradation of ascorbic acid at 850 MPa and 65-80oC followed a first order reaction the rate of ascorbic acid degradation at 850 MPa increased with increasing temperature from 65 to 80C indicating that pressure and temperature act synergistically. Ascorbic acid in tomato juice was more stable than in orange juice. It was also reported that temperature depend- ence of ascorbic acid degradation(z value)was independent of the pressure level Based on this study, it can be concluded that ascorbic acid is unstable at high pressure(850MPa)in combination with high temperature(65-80oC) 21.5.2 Vitamin a and carotene The effect of high pressure treatment on carotene stability has been studied in carrots and in mixed juices. Based on the available literature data, we can con- clude that high pressure treatment does not affect (or affects only slightly) the carotene content in food products. a-and B-carotene contents in carrot puree were only slightly affected by pressure exposure at 600MPa and 75.C for 40 min (Tauscher, 1998). Similar findings have also been reported by de acos and co- workers(2000)showing that carotene loss in carrot homogenates and carrot paste
different influence on the stability of vitamin C during storage. The ascorbic acid content in untreated and pressurised (400 MPa/room temperature/15 min) guava puree started to decline respectively after 10 and 20 days whereas that in heated (88–90°C/24 s) and (600 MPa/room temperature/15 min) pressurised guava purée remained constant during 30 and 40 days respectively (Yen and Lin, 1996). Kinetics of vitamin C degradation during storage have been studied in high pressure treated strawberry coulis. Vitamin C degradation of pressurised (400 MPa/20°C/30 min) and untreated coulis are nearly identical during storage at 4°C. Moreover, it has been shown that a pressure treatment neither accelerates nor slows down the kinetic degradation of ascorbic acid during subsequent storage (Sancho et al, 1999). The effect of oxygen on ascorbic acid stability under pressure has been studied by Taoukis and co-workers (1998). At 600 MPa and 75°C for 40 min exposed to air, ascorbic acid in buffer solution (sodium acetate buffer (0.1 M; pH 3.5–4)) degraded to 45% of its initial content while in the absence of oxygen, less vitamin loss was observed. Moreover, the addition of 10% sucrose resulted in a protective effect on ascorbic acid degradation. It was also noted that vitamin C loss was higher in fruit juice compared to that in buffer solutions. Vitamin C loss in pineapple and grapefruit juice after pressurisation (up to 600 MPa and 75°C) was max. 70% and 50% respectively. At constant pressure (600 MPa after 40min), the pressure degradation of vitamin C in pineapple juice was temperature sensitive, e.g. loss 20–25% at 40°C, 45–50% at 60°C and 60–70% at 75°C in contrast to that in grapefruit juice. Detailed kinetics of combined pressure and temperature stability of ascorbic acid in different buffer (pH 4, 7 and 8) systems and real products (squeezed orange and tomato juices) have been carried out by Van den Broeck and coworkers (1998). At 850 MPa and 50°C for 1 hour, no ascorbic acid loss was observed. The high pressure/thermal degradation of ascorbic acid at 850 MPa and 65–80°C followed a first order reaction. The rate of ascorbic acid degradation at 850 MPa increased with increasing temperature from 65 to 80°C indicating that pressure and temperature act synergistically. Ascorbic acid in tomato juice was more stable than in orange juice. It was also reported that temperature dependence of ascorbic acid degradation (z value) was independent of the pressure level. Based on this study, it can be concluded that ascorbic acid is unstable at high pressure (850 MPa) in combination with high temperature (65–80°C). 21.5.2 Vitamin A and carotene The effect of high pressure treatment on carotene stability has been studied in carrots and in mixed juices. Based on the available literature data, we can conclude that high pressure treatment does not affect (or affects only slightly) the carotene content in food products. a- and b-carotene contents in carrot puree were only slightly affected by pressure exposure at 600 MPa and 75°C for 40 min (Tauscher, 1998). Similar findings have also been reported by de Ancos and coworkers (2000) showing that carotene loss in carrot homogenates and carrot paste 440 The nutrition handbook for food processors
High pressure processing 441 was maximally 5% under pressure condition of 600 MPa/75 C/40 min In orange lemon and carrot mixed juice, high pressure(500 and 800 MPa/room tempera ture/5 min) did not affect or only slightly affected the carotenoid content and during storage at 4C: the carotenoid content in the pressure treated juice remained constant for 21 days(Fernandez Garcia et al, 2001) In addition, high pressure treatment can affect the extraction yield of carotenoids. Studies on persimmon fruit purees showed that high pressure treat- ment could increase the extraction yield of carotenoids between 9 and 27%e.g Rojo Brillante cultivars(50 and 300 MPa/25C/15 min) and Sharon cultivars(50 and 400MPa/25C/15 min). The increase in extraction yield of carotene (40% higher) was also found in pressurised carrot homogenate(600 MPa/25C/10 min) (de Ncos et al, 2000) Pressure stability of retinol and vitamin A has been studied in buffer systems In the model systems studied, pressure treatment could induce degradation of vitamin A. For example, pressures up to 400-600 MPa significantly induced retinol (in 100% ethanol solution) degradation. Degradation up to 45% was obtained after 5 minutes exposure to 600 MPa combined with temperatures at 40 60 and 75C Pressure and temperature degradation of retinol followed a second order reaction. Another study on vitamin A acetate(in 100%o ethanol solution) showed that degradation of vitamin A acetate was more pronounced by increas ing pressure and temperature. About half of the vitamin A acetate concentration could be retained by pressure treatment at different pressure/temperature/time combinations. i.e. 650MPa/70 C/15 minutes and 600 MPa/259C/40 minutes. At 90C, complete degradation was observed after 2-16 minutes(pressure up to 600MPa). No effect of oxygen was noticed on retinol and vitamin A acetate degradation(Butz and Tauscher, 1997; Kubel et al, 1997; Tauscher, 1999) However, findings on retinol pressure stability in real food products differ from those obtained in model systems. In egg white and egg yolk, the initial retinol content can be preserved by pressure treatment from 400 up to 1000 MPa at 5C for 30 minutes(Hayashi et al, 1989) 21.5.3 Vitamins b. e and K The stability of vitamins B, E and K towards pressure treatment has been studied in model systems and food products In food model systems, high pressure(200, 400, 600MPa) treatments at 20C for 30 minutes have no significant effect on vitamin B1(thiamine)and B6(pyridoxal)(Sancho et al, 1999). Studies on the pressure effect on vitamin K showed that small quantities of m-and Diels-Alder products were formed after 3 hours at 650 MPa and 70C(Tauscher, 1999) In cow's milk, high pressure(400 MPa/room temperature/30 minutes)did not alter the content of vitamin B, and B,(pyridoxamine and pyridoxal)(Sierra et al, 2000). The thiamine content in pork meat was not affected by high pressure (100-250MPa/20C/10 minutes)even after long exposure time of 18h at 600 MPa and 20oC(Bognar et al, 1993). However, under extreme conditions of
was maximally 5% under pressure condition of 600 MPa/75°C/40 min. In orange, lemon and carrot mixed juice, high pressure (500 and 800 MPa/room temperature/5 min) did not affect or only slightly affected the carotenoid content and during storage at 4°C; the carotenoid content in the pressure treated juice remained constant for 21 days (Fernández Garcia et al, 2001). In addition, high pressure treatment can affect the extraction yield of carotenoids. Studies on persimmon fruit purées showed that high pressure treatment could increase the extraction yield of carotenoids between 9 and 27% e.g. Rojo Brillante cultivars (50 and 300 MPa/25°C/15 min) and Sharon cultivars (50 and 400 MPa/25°C/15 min). The increase in extraction yield of carotene (40% higher) was also found in pressurised carrot homogenate (600 MPa/25°C/10 min) (de Ancos et al, 2000). Pressure stability of retinol and vitamin A has been studied in buffer systems. In the model systems studied, pressure treatment could induce degradation of vitamin A. For example, pressures up to 400–600 MPa significantly induced retinol (in 100% ethanol solution) degradation. Degradation up to 45% was obtained after 5 minutes exposure to 600 MPa combined with temperatures at 40, 60 and 75°C. Pressure and temperature degradation of retinol followed a second order reaction. Another study on vitamin A acetate (in 100% ethanol solution) showed that degradation of vitamin A acetate was more pronounced by increasing pressure and temperature. About half of the vitamin A acetate concentration could be retained by pressure treatment at different pressure/temperature/time combinations, i.e. 650 MPa/70°C/15 minutes and 600 MPa/25°C/40 minutes. At 90°C, complete degradation was observed after 2–16 minutes (pressure up to 600 MPa). No effect of oxygen was noticed on retinol and vitamin A acetate degradation (Butz and Tauscher, 1997; Kübel et al, 1997; Tauscher, 1999). However, findings on retinol pressure stability in real food products differ from those obtained in model systems. In egg white and egg yolk, the initial retinol content can be preserved by pressure treatment from 400 up to 1000 MPa at 25°C for 30 minutes (Hayashi et al, 1989). 21.5.3 Vitamins B, E and K The stability of vitamins B, E and K towards pressure treatment has been studied in model systems and food products. In food model systems, high pressure (200, 400, 600 MPa) treatments at 20°C for 30 minutes have no significant effect on vitamin B1 (thiamine) and B6 (pyridoxal) (Sancho et al, 1999). Studies on the pressure effect on vitamin K1 showed that small quantities of m- and p-isomeric Diels–Alder products were formed after 3 hours at 650 MPa and 70°C (Tauscher, 1999). In cow’s milk, high pressure (400 MPa/room temperature/30 minutes) did not alter the content of vitamin B1 and B6 (pyridoxamine and pyridoxal) (Sierra et al, 2000). The thiamine content in pork meat was not affected by high pressure (100–250 MPa/20°C/10 minutes) even after long exposure time of 18 h at 600 MPa and 20°C (Bognar et al, 1993). However, under extreme conditions of High pressure processing 441
442 The nutrition handbook for food processors high temperature(100oC)combined with 600MPa, almost 50%o of the thiamine in pork meat was degraded within 15 min. Moreover, riboflavin in pork meat was only slightly affected (less than 20%) after pressure treatment at 600 MPa for 15 minutes combined with temperatures between 25 and 100oC (Tauscher, 1998) Heat-sensitive vitamin derivatives in egg white and/or egg yolk, i.e. riboflavin, folic acid, a-tocopherol and thiamine did not change during pressure treatment from 400 up to 1000 MPa at 25C for 30 minutes(Hayashi et al, 1989) It can be concluded that high pressure treatment has little effect on the vitamin content of food products. However, at extreme conditions of high pressure com- bined with high temperature for a long treatment time period, vitamin degrada- tion is observed. Regarding the use of high pressure in industrial applications, an optimised pressure/temperature/time combination must be chosen to obtain limited vitamin destruction within the constraints of the target microbial inacti- vation. For example, a mild pressure and temperature treatment can be developed equivalent to the conventional pasteurisation processes in order to keep the vitamin content in food products while inactivating vegetative microbial cells When spore inactivation is targeted, combined high pressure thermal treatments are needed and these treatments will affect nutrients. It is still an open question whether equivalent conventional thermal and new high pressure processes used or spore inactivation lead to improved vitamin retention. The available data suggest positive effects but more research is needed 21.6 Effect of high pressure on lipids The most interesting effect of high pressure on lipids in foods is the influence on the solid-liquid phase transition, e.g. a reversible shift of 16.C per 100 MPa for milk fat, coconut fat and lard( Buchheim et al, 1999). With respect to the nutri tional value of lipids, the effect of high pressure on lipid oxidation and hydroly sis in food products is of importance. Lipid oxidation is a major cause of food quality deterioration, impairing both flavour and nutritional values (related to health risks, e.g. development of both coronary heart disease and cancer). Effect of high pressure on lipids has been reported by many authors and the available literature shows that pressure could induce lipid oxidation especially in fish and meat products but did not, or only slightly, affect lipid hydrolysis. For example, pressures up to 1000MPa and 80oC did not affect the hydrolysis of tripalmitin and lecithin. Therefore, no fat/oil hydrolysis is expected to occur under condi- tions relevant for food processing(e.g 600MPa/60 C/time less than 30 minutes) (saacs and Thornton-Allen, 1998) Pressure induced lipid oxidation has been studied in different model systems and food products. In model systems, pressures up to 600 MPa and temperatures up to 40oC (less than 1 hour) had no effect on the main unsaturated fatty acid in milk, i.e. oleic acid. Linoleic acid oxidation was accelerated by exposure to pres sure treatments of less than one hour, but the effect was relatively small(about 10% oxidation)(Butz et al, 1999). Increasing pressure(100 up to 600 MPa and
high temperature (100°C) combined with 600 MPa, almost 50% of the thiamine in pork meat was degraded within 15 min. Moreover, riboflavin in pork meat was only slightly affected (less than 20%) after pressure treatment at 600 MPa for 15 minutes combined with temperatures between 25 and 100°C (Tauscher, 1998). Heat-sensitive vitamin derivatives in egg white and/or egg yolk, i.e. riboflavin, folic acid, a-tocopherol and thiamine did not change during pressure treatment from 400 up to 1000 MPa at 25°C for 30 minutes (Hayashi et al, 1989). It can be concluded that high pressure treatment has little effect on the vitamin content of food products. However, at extreme conditions of high pressure combined with high temperature for a long treatment time period, vitamin degradation is observed. Regarding the use of high pressure in industrial applications, an optimised pressure/temperature/time combination must be chosen to obtain limited vitamin destruction within the constraints of the target microbial inactivation. For example, a mild pressure and temperature treatment can be developed equivalent to the conventional pasteurisation processes in order to keep the vitamin content in food products while inactivating vegetative microbial cells. When spore inactivation is targeted, combined high pressure thermal treatments are needed and these treatments will affect nutrients. It is still an open question whether equivalent conventional thermal and new high pressure processes used for spore inactivation lead to improved vitamin retention. The available data suggest positive effects but more research is needed. 21.6 Effect of high pressure on lipids The most interesting effect of high pressure on lipids in foods is the influence on the solid–liquid phase transition, e.g. a reversible shift of 16°C per 100 MPa for milk fat, coconut fat and lard (Buchheim et al, 1999). With respect to the nutritional value of lipids, the effect of high pressure on lipid oxidation and hydrolysis in food products is of importance. Lipid oxidation is a major cause of food quality deterioration, impairing both flavour and nutritional values (related to health risks, e.g. development of both coronary heart disease and cancer). Effect of high pressure on lipids has been reported by many authors and the available literature shows that pressure could induce lipid oxidation especially in fish and meat products but did not, or only slightly, affect lipid hydrolysis. For example, pressures up to 1000 MPa and 80°C did not affect the hydrolysis of tripalmitin and lecithin. Therefore, no fat/oil hydrolysis is expected to occur under conditions relevant for food processing (e.g. 600 MPa/60°C/time less than 30 minutes) (Isaacs and Thornton-Allen, 1998). Pressure induced lipid oxidation has been studied in different model systems and food products. In model systems, pressures up to 600 MPa and temperatures up to 40°C (less than 1 hour) had no effect on the main unsaturated fatty acid in milk, i.e. oleic acid. Linoleic acid oxidation was accelerated by exposure to pressure treatments of less than one hour, but the effect was relatively small (about 10% oxidation) (Butz et al, 1999). Increasing pressure (100 up to 600 MPa and 442 The nutrition handbook for food processors