Quality assurance in pepper and orange juice blend treated by high pressure processing and high temperature short time

The impact of mixing ratio of pepper juice/orange juice (v/v) at 1:5, 1:2, 1:1, 1:0.5 and 1:0.2 on sensory attributes of pepper and orange juice blend (POJB) was studied, and the ratio of 1:0.5 achieved the highest ratings in mouthfeel and overall acceptability and was chosen for the following study. Effects of high pressure processing (HPP, 550 MPa, 5 min, ambient temperature) and high temperature short time (HTST, 110 °C, 8.6 s) on quality attributes of the POJBs were compared. Reduction of total aerobic bacteria (TAB) and molds and yeasts (M&Y) in the POJBs was > 4 log cycles after HPP and HTST, and the two POJBs were microbiologically safe during the whole refrigerated storage. The color, flavor, appearance, mouthfeel and overall acceptability of HPP-treated POJB were closer to untreated POJB than the HTST-treated one. After 25 days, 77.3% and 75.3% of total phenols content, 90.8% and 90.7% of ascorbic acid, and more than 80% of antioxidant capacity in two POJBs were retained, respectively. Particle size distribution (PSD) of HPP-treated POJB was consistent with untreated POJB (1 ~ 76 μm, 3 peaks at 4.2, 17, 52 μm), while HTST changed the PSD (1 to 33 μm, 2 peaks at 2.4 and 17 μm). Higher level of sedimentation in HPP-treated POJB during storage was interpreted by higher residual PME activity (67.0%) and larger and more unstable pulp particles. The POJBs behaved as Newtonian fluids, their viscosity right after processing were ranked as HPP > untreated > HTST, and the values were slightly reduced during storage.Industrial RelevanceThis study was intended to develop yellow sweet pepper and orange juice blend (POJB), which are not available on the market. Further this study was also intended to explore the application of high pressure processing (HPP) and high temperature short time (HTST) on quality assurance of the POJB. This study would provide technical support for commercialization of juice blend products treated by high pressure.     

Inactivation of food spoilage bacteria and Escherichia coli O157:H7 in phosphate buffer and orange juice using dynamic high pressure

This study aimed to evaluate the potential of dynamic high pressure (DHP) technology to inactivate pathogenic and spoilage microflora in orange juice. Escherichia coli O157:H7 ATCC 35150, Lactobacillus plantarum ATCC 14917, Leuconostoc mesenteroides ATCC 23386 and two orange juice isolates: Saccharomyces cerevisiae and Penicillium ssp. were subjected individually to different DHP treatments. The effectiveness of DHP treatment was first evaluated in phosphate buffered saline (PBS) before application in orange juice samples. The inactivation efficacy of DHP depended on the pressure applied and the number of passes. It was more efficient against Gram-negative strains than Gram-positives. Complete inactivation and 5 log reduction of E. coli O157:H7 were achieved in orange juice at 200 MPa after 5 and 3 passes at 25 °C, respectively. Lower inactivation was obtained with Penicillium ssp. (4 log), S. cerevisiae (2.5 log), L. plantarum (2.3 log) and L. mesenteroides (1.6 log). The gathered results revealed the potential of DHP to inactivate all the tested microorganisms and then, it could constitute a promising alternative technology for cold pasteurization of fruit juices.     

Apple,grape or orange juice: Which one offers the best substrate for lactobacilli growth? — A screening study on bacteria viability,superoxide dismutase activity,folates production and hedonic characteristics

Fermentation can contribute to improve functional aspects of foods. The first goal of this study was to determine amongst apple, grape and orange juices, the one with the best bacterial growth performance during fermentation by Lactobacillus strains from commercial and artisanal food origins, at 40 °C for 48 h. The juice with the highest bacterial growth was evaluated for bacteria viability during 4 weeks of cold storage, superoxide dismutase (SOD) activity and folates production analyzed through HPLC/fluorimetry. Acceptability of fermented juice was appraised through hedonic analysis. Lactobacilli counts were the highest in apple and the lowest in orange juices at t = 48 h. In most cases, bacteria counts were higher in fermented (5.5 to 9.5 log CFU/ml) than in supplemented apple juices (4.2 to 5.7 log CFU/ml), at the 4th week of cold storage. SOD activity was significantly increased in all apple juices fermented by commercial Lactobacilli strains. Folates were produced in apple juices fermented by Lactobacillus plantarum and Lactobacillus rhamnosus. Apple juice was the best substrate for Lactobacillus growth and, considering bacterial viability and overall acceptance by the panelists, Lactobacillus acidophilus L10 was the most suitable strain for apple juice fermentation.     

Supercritical carbon dioxide-treated blood orange juice as a new product in the fresh fruit juice market

The work described here deals with the effectiveness of using high-pressure carbon dioxide treatment (HPCD) to stabilise freshly squeezed blood orange juice. Technical planning of a continuous high-pressure supercritical carbon dioxide pilot system, suitable for development on an industrial scale, was carried out in our lab. To determine the optimal operating conditions (temperature, pressure, and CO₂/juice ratio), three different experimental trials were carried out. The first trial was conducted at 230 bar, 36 ± 1 °C, 5.08 L/h juice flow rate, and 3.91 L/h CO₂ flow rate, corresponding to a g_CO2/g_juice ratio of 0.770. The second trial utilised the same conditions except that the operative pressure was reduced (130 bar). The third trial was carried out at 130 bar, 36 ± 1 °C, 5.08 L/h juice flow rate, 1.96 L/h CO₂ flow rate, corresponding to a 0.385 g_CO2/g_juice ratio. The effects of processing were evaluated by determining physicochemical, antioxidant, and microbiological parameters of the treated juices. In addition, once the best operative parameters had been determined, physicochemical, antioxidant, microbiological and sensory evaluation of fresh blood orange juice stabilised by HPCD treatment was carried out during refrigerated storage of juices at 4 ± 1 °C for thirty days. The results showed that HPCD treatment cannot be considered as an alternative to traditional thermal methods but as a new mild technology for producing a stabilised blood orange juice with a shelf-life of 20 days.Industrial relevanceBlood oranges are the main cultivated varieties of Citrus sinensis (L.) Osbeck in Italy. Freshly squeezed blood orange juice exert a high antiradical and antioxidant activity, due to its rich phenolic profile, but its preservation is usually assured by thermal treatment which affects its nutritional and sensory value. In this study we proposed a “milder” continuous HPCD process suitable for implementation on an industrial scale. The HPCD stabilised juice retains its physicochemical, antioxidant, and sensory properties and could be placed within a new retail framework, namely, that of fresh juices with a shelf-life of 20 days.     

Inactivation of pectin methylesterase and stabilization of opalescence in orange juice by dynamic high pressure

The effect of dynamic high pressure homogenization (DHP) alone or in combination with pre-warming on pectin methylesterase (PME) activity and opalescence stability of orange juice was studied. DHP without heating reduced PME activity by 20%. Warming the juice (50 °C, 10 min) prior to homogenization significantly increased the effectiveness of DHP. PME inactivation was further increased by adjusting the pH downward prior to treatment. Accelerated shelf-life study at 30 °C revealed that opalescence stability can be increased by several days by DHP treatment, even in the presence of active PME. These results suggest that the opalescence stability of orange juice treated by DHP does not depend entirely on PME activity but also on particle size reduction and structural changes to pectin resulting from the treatment. The freshness attributes of orange juice treated by warming was improved by DHP treatment.     

Colour and texture of apples high pressure processed in pineapple juice

Cubes of Granny Smith and Pink Lady apples were vacuum packed in barrier bags with 0% to 50% (v/v) pineapple juice (PJ) at 20°Bx and subjected to high pressure processing (HPP) at 600 MPa for 1–5 min (22 °C). The in-pack total colour change (ΔE) was observed over 4 weeks at 4 °C. Within <1 week of storage at 4 °C, texture, polyphenoloxidase, pectinmethylesterase activities, changes in ΔE and visual browning after opening the bags during air exposure (22 °C; 21% O2 ) for 5 h were also monitored. During the 4 weeks storage in bag visible colour changes were not observed. Texture and ΔE after 5 h air exposure were significantly affected by the apple variety, HPP time and % PJ used. The combined treatment significantly reduced residual PPO activity while PME activity was not affected in both varieties. Pineapple juice in combination with HPP could be used as a natural preservation system for minimally processed apples.Industrial relevanceBrowning upon opening the packs and during air exposure can adversely affect the quality of fresh-cut fruits. Combined treatment of high pressure processing (HPP) and use of pineapple juice has the potential to prevent browning for several hours giving sufficient time for presentation and use in domestic and foodservice environment where high quality fresh-like fruit is required.     

An exploratory study on the influence of orange juice on gut microbiota using a dynamic colonic model

The aim of this research was to evaluate the influence of fresh orange juice (FOJ) and pasteurized orange juice (POJ) on gut microbiota using the Simulator of the Human Intestinal Microbial Ecosystem (SHIME®) in a long-term experiment. SHIME® vessels were used to investigate orange juice fermentation throughout the colon and to assess changes in microbial composition and fermentation metabolites (short-chain fatty acids, or — SCFA, and ammonium). Antioxidant activity of the SHIME® vessels and juice was also evaluated. The FOJ increased (p ≤ 0.05) Lactobacillus spp., Enterococcus spp., Bifidobacterium spp., and Clostridium spp. and reduced (p ≤ 0.05) enterobacteria. The POJ increased (p ≤ 0.05) Lactobacillus spp. and reduced (p ≤ 0.05) enterobacteria. The PCR-DGGE analysis showed a reduction in total bacteria population richness values. The FOJ and POJ increased (p ≤ 0.05) butyric, acetic, and propionic acid concentrations, whereas ammonium production was reduced. High values of antioxidant activity were observed as a result of the FOJ and POJ treatments. Principal component analysis indicated that both POJ and FOJ juices had a positive influence on gut microbiota. The FOJ and POJ were found to exhibit selective prebiotic activity, particularly in terms of gut microbiota. This finding is in agreement with increases in both SCFAs and commensal bacteria, as well as with decreases in ammonium levels, though total bacteria richness values were reduced.     

Study of chemical changes in pasteurised orange juice during shelf-life: A fingerprinting-kinetics evaluation of the volatile fraction

The current work used fingerprinting-kinetics for the first time to monitor shelf-life changes in a low-pH, pasteurised, shelf-stable product, more particular in orange juice. Orange juice samples were stored as a function of time at four different storage temperatures (20, 28, 35 and 42 °C). To obtain insight into chemical changes in the volatile food fraction, samples were fingerprinted with headspace GC–MS. The objectives of this work were twofold: (i) to identify major chemical changes of pasteurised orange juice during shelf-life and (ii) to study the kinetics of selected shelf-life compounds in the context of accelerated shelf-life testing (ASLT). At 20 °C, changes in terpenes and a decrease in aldehydes were observed. Oxides and sulphur compounds increased and esters decreased at increased storage temperatures (at 28 °C and above). Concerning ASLT, four volatile compounds had clear temperature and time dependent kinetics within the investigated temperature range.     

Inactivation of Saccharomyces cerevisiae and Lactobacillus plantarum in orange juice using ultra high-pressure homogenisation

Yeasts and lactic acid bacteria are the usual contaminants in orange juice and responsible for decreasing the shelf life of the product. Ultra high-pressure homogenisation has been shown to be an alternative to the traditional thermal pasteurisation of pumpable foods. The product was pumped through a homogeniser valve at 100 MPa, 150 MPa, 200 MPa, 250 MPa and 300 MPa using two synchronized overlapped intensifiers at a flow rate of approximately 270 mL/min. The inlet temperature was kept at 10 °C, pH at 4.1 and soluble solids at 10.0 °Bx. After processing, the product was immediately cooled to 4 °C and the microbiological count was determined. The study showed that Lactobacillus plantarum and Saccharomyces cerevisiae are sensible to ultra high-pressure homogenisation treatment. The results indicated that pressures higher than 250 MPa were able to completely destroy initial loads of 1.2 × 107 UFC/mL of L. plantarum and 2.9 × 105 UFC/mL of S. cerevisiae in orange juice, making this technology a promising way to nonthermally process orange juices.Industrial relevanceThis paper deals with inactivation of microorganism contaminants of orange juice using dynamic ultra high process technology. It is of industrial interest and relevance to evaluate the use of this non-thermal emerging technology to process fluid foods that may result into better taste, optimum product functionality, safety and quality characteristics.     

Antioxidant capacity,phenolic composition and microbial stability of aronia juice subjected to high hydrostatic pressure processing

The aim of this study was to characterize the effect of high hydrostatic pressure (200–600 MPa/15 min) and storage (4 °C/80 days) on aronia juice quality. The total antioxidant capacity, phenolic content and composition were assessed using an updated analytical strategy. Microbial growth was also analyzed following juice storage. Among all the analyzed juices, the untreated aronia juice had the greatest reduction (36%) in total polyphenols over the entire storage period. At the end of the storage period, the pressurized juices demonstrated ABTS and FRAP values higher by 14% and 5% as compared to the untreated juices. The main antioxidants identified in the aronia juice were: chlorogenic acid; neochlorogenic acid; cyanidin 3-galactoside; cyanidin 3-xyloside; cyanidin 3-arabinoside; cyanidin 3-glucoside. Cyanidin 3-glucoside was the most stable compound during juice storage. Microorganism growth in juices pressurized at 400–600 MPa was below the detection limit (< 1 CFU mL^− 1) upon storage.Industrial relevanceAronia berries are rarely consumed fresh since they give off several negative sensory attributes. Multiple health-promoting properties of aronia berries make them a valuable raw material for juice production. However, processing involves pasteurization or hot-filling strongly diminishes the product quality due to the changes in quantity and quality of thermolabile phytochemicals. The objective of this work was to characterize the effect of high hydrostatic pressure on the antioxidant capacity, polyphenol content and composition and microbial stability of aronia juice. Results of this study may be useful for the juice industry commercialize this technology for the development healthy, nonclarified aronia juices with desired level of quality.     

Fermentative ability of alginate-prebiotic encapsulated Lactobacillus acidophilus and survival under simulated gastrointestinal conditions

Lactobacillus acidophilus was encapsulated in alginate-inulin-xanthan gum and its ability to grow in carrot juice and survive 8 weeks of storage at 4 °C and subsequent exposure to artificial gastrointestinal conditions were assessed. Encapsulation significantly enhanced cell viability after fermentation and storage (6 × 10¹² and 4 × 10¹⁰ cells/ml versus 4 × 10¹⁰ and 2 × 10⁸ for free cells, respectively). Encapsulation protected L. acidophilus from exposure to simulated gastric conditions; minor alterations in viability and the protein profile occurred after incubation in pancreatic juice. For free cells, viability decreased significantly and the expression of numerous proteins was lost after incubation in gastric and pancreatic juice. Thus, encapsulation preserved probiotic bacterial viability and activity; the addition of inulin as a prebiotic component could enhance the functional properties of food products containing this formulation.     

Assessing the acid tolerance and the technological robustness of probiotic cultures for fortification in fruit juices

The suitability of probiotic cultures as fruit juice supplements was examined by assessing their acid tolerance and technological robustness. Survival of Lactobacillus and Bifidobacterium strains in orange juice (OJ), pineapple juice (PJ) and cranberry juice (CJ) was monitored. Results revealed that extensive differences exist among probiotic strains regarding their acid resistance. All of the strains screened survived for longer in OJ and PJ compared to CJ. L. casei DN-114 001, L. rhamnosus GG and L. paracasei NFBC43338 displayed the greatest robustness surviving at levels above 10⁷ cfu ml^− 1 in OJ and above 10⁶ cfu ml^− 1 in PJ for at least 12 weeks. Probiotic tolerance to thermal and non-thermal processing was studied to determine the feasibility of their addition to OJ prior to pasteurisation. OJ fortified with probiotic cultures was subjected thermal pasteurisation at 76 °C for 30 s and 90 °C for 1 min in addition to a high pressure treatment of 400 MPa for 5 min. Results indicated no strain was capable of withstanding treatments necessary to achieve a stable juice at levels > 10⁶ cfu ml^− 1. The outcome of the overall study points to L. rhamnosus GG, L. casei DN-114 001 and L. paracasei NFBC43338 as having promising potential for exploitation as functional supplements in fruit juices due to their impressive tolerance in acidic environments; however, fortification post processing is recommended.Industrial relevanceThe ability of health-promoting cultures to survive for at least 12 weeks in orange juice and pineapple juice at commercially critical levels renders them suitable strains for exploitation. Their inclusion may enhance the market potential of these already successful beverages.     

Flavanone glycosides in Brazilian orange juice

Authentic samples of oranges, frozen concentrated orange juice and pulp-wash, and retail samples of freshly squeezed orange juice and frozen concentrated orange juice have been collected in Brazil and analysed for the flavanone glycosides (FG) narirutin and hesperidin by reversed phase HPLC with UV detection at 280 nm. The juice from hand-squeezed fruit gave narirutin and hesperidin concentrations of 16–142 mg l⁻¹ and 104–537 mg l⁻¹, respectively. The ratio of hesperidin to narirutin showed varietal difference with Pera having the highest ratio (mean 8.4) and Baı́a the lowest (3.6). Frozen concentrated orange juice contained higher quantities of FG with narirutin ranging from 62 to 84 mg l⁻¹ and hesperidin from 531 to 690 mg l⁻¹ (after dilution to 12 °Brix). In frozen concentrated orange juice pulp-wash, the narirutin level ranged from 155 to 239 mg l⁻¹ and hesperidin from 1089 to 1200 mg l⁻¹. The analysis of 23 samples of freshly squeezed juice from the Brazilian market place showed that the FG content of most samples (9.1 to 94.8 and 105.8 to 586.6 mg l⁻¹, respectively, for narirutin and hesperidin) was similar to those found for authentic ones, indicating that these orange juices were not adulterated.     

Comparison of multiple chemical sanitizers for reducing Salmonella and Escherichia coli O157:H7 on spinach (Spinacia oleracea) leaves

Effectiveness of multiple chemical sanitizers on the reduction of Salmonella spp. and Escherichia coli O157:H7 on spinach was compared. Fresh spinach (Spinacia oleracea) was inoculated with a bacterial suspension containing multiple strains of rifampin-resistant Salmonella and E. coli O157:H7. Inoculated spinach leaves were treated with a water wash or water wash followed by 2% L-lactic acid at 55 °C, peroxyacetic acid (80 mg/L), calcium hypochlorite (200 mg/L), ozonated water (mg/L) or ClO₂ gas (1.2 or 2.1 mg/L). The l-lactic acid produced a 2.7 log CFU/g reduction for E. coli O157:H7 and a 2.3 log CFU/g reduction for Salmonella, statistically significant compared to water wash alone (P < 0.05), which resulted in a reduction of 0.7 log CFU/g for both pathogens. These findings indicate that 2% l-lactic acid at 55 °C may be an effective treatment for reducing pathogens on spinach leaves.     

Comparative study on cloudy apple juice qualities from apple slices treated by high pressure carbon dioxide and mild heat

Qualities of cloudy apple juices from apple slices treated by high pressure carbon dioxide (HPCD) and mild heat (MH) were evaluated. Temperatures were from 25 to 65 °C, time 20 min, and pressure 20 MPa. Polyphenol oxidase (PPO) was completely inactivated by HPCD and its minimal residual activity (RA) by MH at 65 °C was 38.6%. RA of pectin methylesterase (PME) with HPCD was significantly lower than MH and its minimum was 18%. L value of cloudy apple juice from HPCD-treated apple slices was significantly greater than that from MH-treated apple slices, however, b value, browning degree (BD) and turbidity were lower. And no differences in a value, total soluble solids, pH and conductivity were observed. After 7-day storage at 4 °C, HPCD caused no BD alteration but a significant turbidity loss. MH increased BD at 55 and 65 °C, and led to turbidity loss from 35 to 65 °C. The turbidity was not well related to RA of PME.Industrial relevanceCloudy apple juice is one of the popular fruit juices, and it requires strict processing treatment conditions to protect its quality, especially to prevent enzymatic browning and cloud loss. HPCD is one promising novel non-thermal technique and is likely to replace or partially substitute thermal processes. This study analyzed the effect of HPCD as a pretreatment means on qualities of cloudy apple juice, including inactivating enzymes which are crucial to quality control. Available data provided in this study will benefit the fruit juice industry.     

Change of microbial and quality attributes of mango juice treated by high pressure homogenization combined with moderate inlet temperatures during storage

The effects of high pressure homogenization (HPH) on microbial inactivation and quality attributes (physio-chemical properties, bioactive components and antioxidant capacity) of mango juice, as well as their changes during storage at 4 °C and room temperature were investigated. Pressure levels ranged from 40 to 190 MPa, the inlet temperature from 20 °C to 60 °C and the number of passes from 1 to 5. Complete inactivation of molds and yeasts was achieved by 1 and 3 passes at 190 MPa and 60 °C, while total plate count was below 2.0 log₁₀ CFU/mL. No multiplication of microorganisms was observed in mango juice over 60 days of storage at 4 °C. HPH treatment could retain or even increase the carotenoids and total phenols by 11.8% and 21.4%, respectively, while significant reductions were found for heat treatment (HT) samples. During the storage of 60 days, HPH treatment also provided better preservation of color, bioactive components and antioxidant capacity of mango juice than HT.Industrial relevanceHigh pressure homogenization (HPH) is a novel non-thermal technique, particularly suitable for continuous production of liquid foods limiting thermal damage and promoting “freshness”. Results showed that high pressure homogenization had the advantage of notably reducing the microbial load to levels equivalent to thermal pasteurization. Moreover, HPH treatment was superior to heat treatment with regard to post-treatment levels of bioactive.     

Fat contributes to the buffering capacity of chicken skin and meat but enhances the vulnerability of attached Salmonella cells to acetic acid treatment

Chicken skin and chicken meat display different buffering effects which may impact the survival of Salmonella attached to them when treated with acids. This study investigated the role that differences in fat composition of chicken skin and meat play in their buffering capacity. The survival of Salmonella attached to chicken skin and meat in the presence of fat, and treated with acetic acid was also investigated. Fat was extracted from chicken skin and meat and the buffering capacities of chicken skin, meat, extracted fat and their respective remnants were determined. Two strains of Salmonella Typhimurium and two strains of S. Enteritidis were attached independently to each of the chicken component listed above and enumerated before and after treatment with 0.3 M acetic acid. Chicken skin has a higher fat content as compared to chicken meat. Skin (13 mmol H⁺/(pH1 kg)) had a stronger buffering capacity (p < 0.05) than the extracted fat alone and skin remnants alone (7.0 mmol H⁺/(pH 1 kg) and 6.9 mmol H⁺/(pH 1 kg) respectively). From an initial inoculum (~ 9 log CFU/g), Salmonella cells attached better (p < 0.05) to chicken meat (~ 8 log CFU/g) and chicken skin (~ 7 log CFU/g) than extracted fat (~ 1.5 log CFU/g). Skin remnants without fat were better (p < 0.05) at protecting attached Salmonella than other chicken components. For example S. Typhimurium ATCC 33062 decreased ~ 1 log CFU/g (p < 0.05) on skin remnants after acetic acid treatment while its viable counts on other components decreased from ~ 1.5 to 7 log CFU/g (p < 0.05). We suggest that the fat content present in the skin may enhance the vulnerability of attached cells to acetic acid.     

Survival of Salmonella Enteritidis PT 30 on inoculated almond kernels in hot water treatments

Almonds are blanched by exposure to hot water or steam-injected water to remove the pellicle (skin) from the kernel. This study evaluated the survival of Salmonella Enteritidis PT 30, Salmonella Senftenberg 775W and Enterococcus faecalis on whole raw almond kernels exposed to hot water. Whole, inoculated (7 to 9 log CFU/g) Nonpareil almonds (40 g) were submerged in 25 L of water maintained at 60, 70, 80 and 88 °C. Almonds were heated for up to 12 min, drained for 2 s, and transferred to 80 mL of cold (4 °C) tryptic soy broth. Almonds in broth were stomached at high speed for 2 min, serially diluted, plated onto tryptic soy and bismuth sulfite agars (Salmonella) or bile esculin agar (Enterococcus) and incubated at 37 °C for 24 and 48 h, respectively. D values of 2.6, 1.2, 0.75 and 0.39 min were calculated for exposure of S. Enteritidis PT 30 to water at 60, 70, 80 and 88 °C, respectively; the calculated z value was 35 C°. D values determined for Salmonella Senftenberg 775W and E. faecalis at 88 °C were 0.37 and 0.36 min, respectively. Neither Salmonella serovar could be recovered by enrichment of 1-g samples after almonds inoculated at 5 log CFU/g were heated at 88 °C for 2 min. These data will be useful to validate almond industry blanching processes.     

Effect of chill storage and modified atmosphere packaging (MAP) on antioxidant activity,anthocyanins, carotenoids,phenolics and sensory quality of ready-to-eat shredded orange and purple carrots

Ready-to-eat shredded orange and purple carrots, packed in air (control), or in modified atmosphere packaging [MAP; (90%N₂ + 5%O₂ + 5%CO₂ and 95%O₂ + 5%CO₂)], and stored chilled for up to 13 days, were examined for their antioxidant activity and contents of anthocyanins, carotenoids and phenolics, as well as sensory quality. Total antioxidant activity, carotenoids and phenolics of purple carrots were initially 2.8-, 2.3- and 2.9-fold higher than orange carrots, respectively. Total antioxidant activity remained relatively constant in orange carrots during storage under all treatment conditions, whereas a highly significant decrease (P<0.01) in (95%O₂ + 5%CO₂)-treated purple carrots was observed. The content of anthocyanin, only found in purple carrots, was decreased slightly during the storage period, and this was particularly significant in the 95%O₂ + 5%CO₂ treatment. In both orange and purple carrots, loss of total carotenoids occurred in the 95%O₂ + 5%CO₂ treatment. Total phenolic content of purple carrots increased at a much higher rate during storage than orange carrots. The MAP treatment (90%N₂ + 5%O₂ + 5%CO₂) gave better sensory quality and extended shelf-life for purple carrots (∼2–3 days longer shelf-life than other treatments,) but, no difference was observed for orange carrots. Shredded purple carrot can be stored under 90%N₂ + 5%CO₂ + 5%O₂ treatment for up to 10 days and high nitrogen treatment may be used in maintaining the storage quality of shredded purple carrots. Thus, purple carrots may be used in place of orange carrots to take advantage of their nutraceutical components.