Comparative Effects of Thermal, High Hydrostatic Pressure, and UV-C Processing on the Quality, Nutritional Attributes, and Inactivation of Escherichia coli, Salmonella, and Listeria Introduced into Tiger Nut Milk

ABSTRACT Tiger nut milk is a low-acid health beverage that is marketed with the claims of being high in protein, monounsaturated fatty acid (oleic acid), fiber, starch, and minerals, in addition to vitamins C and E. In this study, the effect of nonthermal processing with UV light (UV-C) or high hydrostatic pressure (HHP) on the nutritive content (protein, vitamin C, polyphenols, and antioxidant), and quality characteristics (viscosity and color) of tiger nut milk were compared with thermal processing. Baseline studies established the treatments parameters to support a >5-log CFU reduction of Escherichia coli P36, Listeria innocua ATCC 51742, and Salmonella Typhimurium WG49 introduced into tiger nut milk and then treated with thermal or nonthermal methods. The thermal treatment at 60°C for 30 min, HHP at 500 MPa for 120 s, and UV-C at 45.2 mJ cm−2 were required to achieve the target 5-log reduction. Thermal treatment resulted in a significant loss (P < 0.05) of total protein (34.9%), total phenolic content (28.7%), and vitamin C (27.1%) and negatively affected the tiger nut milk color, along with decreasing its viscosity. In contrast, HHP and UV-C light treatment retained protein and antioxidant content in tiger nut milk with no significant (P > 0.05) color change being recorded. Therefore, from a processing prospective, either UV-C light or HHP could be used to treat tiger nut milk, although additional hurdles to control the potential outgrowth of Clostridium botulinum during storage would be required. HIGHLIGHTS

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High Hydrostatic Pressure Processing Better Preserves the Nutrient and Bioactive Compound Composition of Human Donor Milk

Journal of Nutrition ◽

10.1093/jn/nxy302 ◽

2019 ◽

Vol 149 (3) ◽

pp. 497-504 ◽

Cited By ~ 11

Author(s):

Michael A Pitino ◽

Sharon Unger ◽

Alain Doyen ◽

Yves Pouliot ◽

Susanne Aufreiter ◽

...

Keyword(s):

Hydrostatic Pressure ◽

Vitamin C ◽

Human Milk ◽

High Hydrostatic Pressure ◽

Very Low Birth Weight ◽

Future Research ◽

Low Birth Weight Infants ◽

Human Donor ◽

Donor Milk ◽

Uv C

ABSTRACT Background When mother's milk is insufficient, pasteurized human donor milk (DM) is the recommended supplement for hospitalized very-low-birth-weight infants. The current method of pasteurization (Holder, 62.5°C, 30 min) negatively affects heat-sensitive nutrients and bioactive proteins. Objectives Objectives of this study were to compare changes in DM composition after thermal pasteurization (Holder and flash-heating) and nonthermal methods [UV-C irradiation and high hydrostatic pressure (HHP)]. We hypothesized that nonthermal techniques would result in fewer changes to composition. Methods Holder, flash-heating (brought to boil), UV-C irradiation (250 nm, 25 min), and HHP (500 MPa, 8 min) were studied. Pools of milk from 17 women known to contain bacteria at >5 × 107 colony forming units (CFU)/L were collected from the Rogers Hixon Ontario Human Milk Bank and underwent each pasteurization technique. Macronutrients, heat-sensitive micronutrients (vitamin C, folate), and bioactive components [bile-salt-stimulated lipase (BSSL), lysozyme, lactoferrin] were measured in raw and pools of pasteurized milk. Milk was cultured to determine how well each technique produced a culture negative result (detection limit <1 × 103 CFU/L). Results Folate was reduced by 24–27% after Holder, flash-heating, and UV-C (P < 0.05); no reduction was observed after HHP. All pasteurization methods reduced vitamin C (60–75%, P < 0.001). BSSL was abolished after Holder and flash-heating (P < 0.001), reduced after UV-C (48%, P < 0.001), but unaffected by HHP. Lysozyme activity was reduced after flash-heating (44%) and UV-C (74%, P < 0.004) but unaffected by Holder or HHP. Lactoferrin was reduced by all methods (P < 0.02) but most severely by flash-heating (74%) and least severely by HHP (25%). Holder and UV-C reduced lactoferrin by ∼48%. All pasteurization methods reduced the number of culture positive DM samples (P < 0.001). Conclusions HHP better preserves human milk composition than Holder pasteurization. Future research on the feasibility of HHP for pasteurizing human milk is warranted because its implementation may improve the nutritional status and health of DM-fed infants.

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Enzymatic and phytochemical stabilization of orange–strawberry–banana beverages by high hydrostatic pressure and mild heat

Food Science and Technology International ◽

10.1177/1082013216678537 ◽

2016 ◽

Vol 23 (2) ◽

pp. 185-193 ◽

Cited By ~ 4

Author(s):

Zamantha Escobedo-Avellaneda ◽

Izaskun Pérez-Simón ◽

María Lavilla-Martín ◽

Ana Baranda-González ◽

Jorge Welti-Chanes

Keyword(s):

Ascorbic Acid ◽

Hydrostatic Pressure ◽

Thermal Treatment ◽

Polyphenol Oxidase ◽

High Hydrostatic Pressure ◽

Total Phenolic Content ◽

Phenolic Content ◽

Ascorbic Acid Content ◽

Pectin Methylesterase ◽

Total Phenolic

A new approach to the use of high hydrostatic pressure is its combination with high and intermediate temperatures applied to obtain safe foods of high quality. The effect of high hydrostatic pressure on color, residual polyphenol oxidase and pectin methylesterase activity, and total phenolic and l-ascorbic acid contents of orange–strawberry–banana beverages was evaluated. Beverages were treated at 500 and 600 MPa at 19–64 ℃ during 2–10 min. The effect of the come up time was also evaluated and results were compared with the untreated and the thermally processed (80 ℃/7 min) products. Untreated beverages had total phenolic content of 210.2±12.3 mg gallic acid/100 g and 19.1 ± 0.6 mg l-ascorbic acid/100 g. For most high hydrostatic pressure treatment conditions, total phenolic content, l-ascorbic acid, and color did not change significantly. Maximum levels of inactivation of polyphenol oxidase and pectin methylesterase were 96.2 and 48% at 600 MPa/64 ℃/10 min, while the thermal treatment led to inactivation of 99.6 and 94.1% of both enzymes, but with negative color changes. l-ascorbic acid content was slightly decreased with the thermal treatment while total phenolic content was not affected. High hydrostatic pressure treatments of beverages at 600 MPa/64 ℃/10 min are recommended to retain maximal total phenolic content and l-ascorbic acid and achieve an acceptable polyphenol oxidase inactivation level.

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Survival of mouse blastocysts after low-temperature preservation under high pressure

Acta Veterinaria Hungarica ◽

10.1556/avet.52.2004.4.10 ◽

2004 ◽

Vol 52 (4) ◽

pp. 479-487 ◽

Cited By ~ 7

Author(s):

Cs. Pribenszky ◽

M. Molnár ◽

S. Cseh ◽

L. Solti

Keyword(s):

Phase Transition ◽

Hydrostatic Pressure ◽

Low Temperature ◽

High Hydrostatic Pressure ◽

Room Temperature ◽

Freezing Point ◽

Significant Loss ◽

Embryo Cryopreservation ◽

Subzero Temperatures ◽

Survival Capacity

Cryoinjuries are almost inevitable during the freezing of embryos. The present study examines the possibility of using high hydrostatic pressure to reduce substantially the freezing point of the embryo-holding solution, in order to preserve embryos at subzero temperatures, thus avoiding all the disadvantages of freezing. The pressure of 210 MPa lowers the phase transition temperature of water to -21°C. According to the results of this study, embryos can survive in high hydrostatic pressure environment at room temperature; the time embryos spend under pressure without significant loss in their survival could be lengthened by gradual decompression. Pressurisation at 0°C significantly reduced the survival capacity of the embryos; gradual decompression had no beneficial effect on survival at that stage. Based on the findings, the use of the phenomena is not applicable in this form, since pressure and low temperature together proved to be lethal to the embryos in these experiments. The application of hydrostatic pressure in embryo cryopreservation requires more detailed research, although the experience gained in this study can be applied usefully in different circumstances.

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