Microbiology of wheat and flour milling in Australia

A survey was undertaken to determine the microbiological status of Australian wheat and the distribution of microorganisms in the flour milling fractions and end products. A total of 650 milling process and end product samples was obtained from nine flour mills located in New South Wales (4), Queensland (2), Victoria (2) and Western Australia (1) during the 1997-1998 and 1998-1999 wheat seasons. Most frequent (modal) counts in wheat and flour were, respectively, as follows: aerobic mesophilic plate count, 10(5) and 10(2) colony forming units/gram (cfu/g); coliforms, 10 and 1 most probable number/gram (MPN/g); Bacillus spp., 10(4) and 10(2) cfu/g; B. cereus, 1 and 0.1 MPN/g; mesophilic aerobic spores, 10 and 1 cfu/g; aerobic thermophiles, both 10 cfu/g; yeasts, 10(3) and 10(2) cfu/g, and moulds, 10(3) and 10(2) cfu/g. Bacillus spp., coliforms, yeasts and moulds were the most frequently detected microorganisms throughout the survey. The most common moulds isolated were Aspergillus, Penicillium, Cladosporium and Eurotium spp. Environmental serovars of Salmonella were isolated from two samples. Escherichia coli and B. cereus were present at very low levels, a majority of positive samples being at the minimum level of detection (3 and 0.3 MPN/g, respectively). As wheat grain layers are separated, surface-adhering contaminants are concentrated in end product bran, wheat germ and pollard, which comprise the outer layers of the grain. Consequently, the inner endosperm fraction contains lower microbial counts, and flour is the cleanest end product of the milling process. Higher microbiological counts midstream in the milling process indicate that equipment contamination may contribute to microbiological contamination; however, the microbiological quality of incoming wheat has a strong influence on the ultimate quality of milling end products.     

A survey of ethnic foods for microbial quality and content aflatoxin

A range of ethnic foods was examined for their microbiological content in relation to total viable counts (TVC) of aerobic bacteria, counts of presumptive coliforms, yeast and mould counts; presence of Salmonella spp., Listeria monocytogenes, Escherichia coli 0157:H7 and Campylobacter spp.; total enumeration of Clostridium perfringens, Staphylococcus aureus and Bacillus spp.; identification of moulds and the presence of total aflatoxins. Samples, which included cereals, nuts, dried fruits, herbs and spices, were obtained from local retail outlets and distributors. It was established that three samples of pistachio nuts contained significant levels of aflatoxins. The concentration of total aflatoxins in these three nut samples ranged from 15 to 259 mu g/kg of sample. Only two other samples contained trace amounts of aflatoxins, all other samples analysed were found to be free of any detectable level of aflatoxins. TVCs, coliform counts and yeast and mould counts varied widely depending on the matrix tested. Generally, rice, wheat and peanuts produced low counts whereas other nuts, gram flour and spices produced much higher counts. Cl. perfringens, Staph. aureus , and Bacillus spp. were common in spices, nuts and gram flour, however, Listeria monocytogenes was only detected in four samples and in no sample could Salmonella spp, E. coli 0157:H7 or Campylobacter spp. be detected.     

Assessment of the microbiological quality and wash treatments of lettuce served in University restaurants

One hundred and forty-four samples of lettuce from 16 University restaurants were analyzed. The mesophilic aerobic counts of all samples ranged from 3.01 to 7.81 log10 CFU g(-1). Results of total coliforms ranged from < 0.47 to > 3.38 log10 most probable number (MPN) g(-1). Of the lettuce samples, 25.7% harbored Escherichia coli, 22.9% Staphylococcus aureus and 84% group D streptococci. Similarly, 10.4% of the samples harbored Aeromonas hydrophila, 2.8% Pseudomonas aeruginosa, and coliforms such as 14.6% Citrobacter freundii, 8.3% Klebsiella pneumoniae, 4.2% Enterobacter cloacae and 1.4% Providencia spp. Salmonella, Shigella and E. coli O157:H7 were not detected. When sodium hypochlorite or potassium permanganate solutions were used in washing procedures, the aerobic microorganisms were reduced by more than two log units, and total coliforms by at least one log.     

Microbiological survey of retail herbs and spices from Mexican markets

In the present study, 304 samples of herbs and spices (garlic powder, cumin seeds, black pepper, oregano, and bay leaves) widely used in Mexico were analyzed for the presence of Bacillus cereus, Salmonella Typhi, Shigella dysenteriae, Escherichia coli, total and fecal coliforms, total mesophilic aerobic organisms, and fungi. Samples were nonpackaged or packaged in polyethylene bags or glass containers. High levels (10(5) to 10(7) CFU/g) of mesophilic aerobic microorganisms were found in most of the samples of garlic powder, cumin seed, and black pepper. Lower levels (<102 CFU/g) were found in oregano and bay leaves. Total and fecal coliforms counts were dependent on the type of packaging. More than 70% of the polyethylene-packaged samples had less than 10(3) CFU/g of microorganisms. Glass and nonpackaged spices showed lower levels of these microorganisms. B. cereus was present in 32 samples of which most were polyethylene packaged. The other pathogenic bacteria were not detected. Aspergillus niger was detected in 29% of the samples, Rhizopus sp. in 19%, and Penicillum sp. and Cunninghamella in 8%.     

Use of natural compounds to improve the microbial stability of Amaranth-based homemade fresh pasta

A study on the use of natural antimicrobial compounds to improve the microbiological stability of refrigerated amaranth-based homemade fresh pasta is presented in this work. In particular, the antimicrobial activity of thymol, lemon extract, chitosan and grapefruit seed extract (GFSE) has been tested against mesophilic and psychrotrophic bacteria, total coliforms, Staphylococcus spp., yeasts and moulds. A sensory analysis on both fresh and cooked pasta was also run. Results suggest that chitosan and GFSE strongly increase the microbial acceptability limit of the investigated spoilage microorganisms, being the former the most effective. Thymol efficiently reduces the growth of mesophilic bacteria, psychrotrophic bacteria and Staphylococcus spp., whereas it does not affect, substantially, the growth cycle of total coliforms. Lemon extract is the less effective in preventing microbial growth. In fact, it is able to delay only total mesophilic and psychrotrophic bacterial evolution. From a sensorial point of view no significant differences were recorded between the control samples and all the types of loaded amaranth-based pasta.     

Microbiological quality of ayib, a traditional Ethiopian cottage cheese

One-hundred samples of ayib, a traditional Ethiopian cottage cheese, were purchased from Awassa market and analysed for their aerobic mesophilic counts, psychrotropic counts, yeasts and molds, coliforms, spore-formers, enterococci, lactic acid bacteria, Listeria monocytogenes, staphylococci and Bacillus cereus. The majority of the samples showed counts of mesophilic aerobic bacteria, yeasts and enterococci of 10⁸, 10⁷ and 10⁷ cfu/g. About 55% of the samples were positive for coliforms and faecal coliforms. Listeria spp. were not detected in any of the samples. B. cereus and S. aureus were isolated at varying frequencies but at low numbers (10²–10³). The pH value of the samples varied between 3.3 and 4.6 with about 40% having pH lower than 3.7.     

Microbiological condition of ground meat retailed in Monterrey, Mexico

Eighty-eight samples of ground meat were randomly collected from retail stores in the metropolitan area of Monterrey, Mexico, and were analyzed for microbial contamination. Methods were those recommended by the Mexican regulation and/or the U.S. Food and Drug Administration. Over 75% of the samples contained > 10(5) total mesophilic microorganisms per g, and over 40% had >10(6) total coliforms per g. Fecal coliforms were present in most samples. Staphylococcus aureus was detected in 2.3% of the samples, Salmonella spp. in 11.4%, Listeria spp. in 62%, and L. monocytogenes in 16%. Escherichia coli was detected in 76% of samples, but none was serotype O157:H7. Shigella spp. was not found in any sample. Fusarium spp. and Mucor spp. were detected in 3.4% of the samples, and low levels of yeast in 93%. The microbiological quality of the ground meat analyzed was unsatisfactory, and the product could be an important cause of food poisoning.     

The effects of starter culture on chemical composition, microbiological and sensory characteristics of Turkish Kaşar Cheese during ripening

Kaşar cheese samples were produced from raw milk and starter culture-added pasteurized milk. Chemical, microbiological and organoleptic properties of kaşar cheeses were analysed at certain times during the ripening periods (on the 1st, 7th, 15th, 30th, 60th, 90th days). Generally, chemical parameters were not affected by starter culture. The pH, ripening index, water-soluble nitrogen and non-protein nitrogen did not show significant differences between the cheese samples. The addition of starter affected the microbiological quality of the cheeses. Starter culture-added kaşar cheeses contained low levels of total aerobic mesophilic bacteria, moulds and yeasts, and coliforms, and achieved higher organoleptic scores than those of cheeses made from raw milk. The starter cultures contributed to acidity and microbial quality of the cheese.     

High-pressure processing of Turkish white cheese for microbial inactivation

High-pressure processing (HPP) of Turkish white cheese and reduction of Listeria monocytogenes, total Enterobacteriaceae, total aerobic mesophilic bacteria, total molds and yeasts, total Lactococcus spp., and total Lactobacillus spp. were investigated. Cheese samples were produced from raw milk and pasteurized milk and were inoculated with L. monocytogenes after brining. Both inoculated (ca. 10(7) to 10(8) CFU/g) and noninoculated samples were subjected to HPP in a high-pressure food processor at 50 to 600 MPa for 5 and 10 min at 25 degrees C. Reductions in L. monocytogenes, total aerobic mesophilic bacteria, Lactococcus spp., and Lactobacillus spp. in both pasteurized- and raw-milk cheese samples and reductions in total molds and yeasts and total Enterobacteriaceae counts in raw-milk cheese samples increased with increased pressure (P < or = 0.05). The maximum reduction of the L. monocytogenes count, ca. 4.9 log CFU/g, was obtained at 600 MPa. Because of the highly inhibitory effect of pasteurization, the total molds and yeasts and total Enterobacteriaceae counts for the cheese samples produced from pasteurized milk were below the detection limit both before and after HPP. There was no significant difference in inactivation of L. monocytogenes, total aerobic mesophilic bacteria, Lactococcus spp., and Lactobacillus spp. under the same treatment conditions for the raw milk and pasteurized milk cheeses and for 5- and 10-min treatment times (P > 0.05). No significant change was detected in pH or water activity of the samples before and after HPP. Our findings suggest that HPP can be used effectively to reduce the microbial load in Turkish white cheese.     

Microflora of minimally processed frozen vegetables sold in Gaborone, Botswana

Two hundred samples of minimally processed, frozen, and prepacked potato chips, peas, corn, and a variety of combined vegetables from supermarkets in Gaborone, Botswana, were examined microbiologically. Determination of aerobic mesophilic plate count, aerobic psychrotrophic plate count, lactic acid bacteria, yeasts and molds, coliforms, Listeria spp., and Staphylococcus aureus were done. Chips had the lowest mean log values for all of the microorganisms enumerated except yeasts and molds. The mean log values for single vegetables ranged from 3.6 to 9.1, 3.4 to 8.9, 2.9 to 5.6, and 2.1 to 6.5 log CFU/ g aerobic mesophilic plate count, aerobic psychrotrophic plate count, lactic acid bacteria, and yeasts and molds, respectively. The microbial profiles of peas and corn were almost similar (P < 0.001). The mean values for combined vegetables were clustered within 4.6 and 5.4 and 4.2 and 5.2 log CFU/g aerobic mesophilic plate count and aerobic psychrotrophic plate count, respectively. All of the vegetables had a coliform population distribution ranging from 0 to < 10(4) most probable number per g. The predominant gram-negative bacteria isolated included members of Enterobacteriaceae and Pseudomonaceae (86.2%). Escherichia coli was not detected in all of the samples. The organisms isolated included those responsible for spoilage in frozen vegetables, namely Pseudomonas, Klebsiella, Corynebacterium, lactic acid bacteria, and Flavobacterium. The predominant lactic acid bacteria were Lactobacillus spp. (55.9%). Other spoilage organisms were yeasts, and Cryptococcus spp. (55.4%) was predominant. Pathogens, namely Listeria monocytogenes, were also isolated at a rate of 2 to 10%, of which 4% was from corn, 2% each from peas and country crop, and 10% from stir-fry. Bacillus cereus was also isolated and accounted for 7.7% of the microorganisms from corn. S. aureus was isolated from all of the vegetables. Enterotoxigenic strains were from corn, peas, mixed vegetables, and stir-fry, and all of them produced enterotoxin A. In addition, the isolates from stir-fry vegetables also produced enterotoxins B and C. The study reveals the presence of pathogens and emerging opportunistic pathogens in the ready-to-use or ready-to-eat vegetables. If E. coli is the only indicator for safety and acceptability, consumers may be exposed to foodborne diseases. Inclusion of other groups as indicator organisms is suggested. Retailers are urged to invest in standby generators to maintain the cold chain.     

The microbiological quality of Erzincan (Savak) Tulum cheese from Turkish retail markets

Twenty samples of Erzincan (Savak) Tulum cheese were investigated for the microbiological quality and some chemical analyses. Cheese was characterized by moisture content means = 45.0%; 3.27% sodium chloride and 2.14% acidity. Significant variation was found in the major compositional factors indicating a general lack of quality and/or extreme diversity of the manufacturing conditions. Microbiological test revealed the presence of very high count of total coliforms, psychrotrophic bacteria, yeasts and moulds, high numbers of Staphylococcus aureus and Clostridium perfringens but no salmonellas. Statistical relationship between growth and counts, and the presence of other indicators, pathogens, and compositional factors was investigated.     

Bacterial populations associated with a sorghum-based fermented weaning cereal.

Microbiological surveys, to determine the quality and safety, were conducted on 45 sorghum samples comprising dry powders (n = 15) and corresponding fermented (n = 15) and cooked fermented porridge (n = 15) samples collected from households in an informal settlement of the Gauteng Province of South Africa. Mean aerobic plate counts, Gram-negative counts and bacterial spore counts of sorghum powder samples decreased in fermented and cooked fermented porridge samples. However, mean lactic acid bacteria counts increased in fermented porridge samples, but decreased slightly in cooked fermented porridge samples. The mean pH value of sorghum powder samples decreased in fermented and cooked fermented porridge, respectively. Bacillus (B.) cereus was detected in all 15 sorghum powder samples, while Escherichia (E.) coli was detected in 53%, Clostridium perfringens in 27%, Listeria monocytogenes in 13% and Aeromonas spp., Salmonella spp., Staphylococcus aureus, Shigella spp. and Yersinia spp., each in 7% of sorghum powder samples. Of the fermented porridge samples, 40% contained B. cereus and 7% contained E. coli. None of the pathogens tested for were detected in cooked fermented porridge samples. B. cereus (53%), B. subtilis (21%), B. thuringiensis (13%), B. licheniformis (10%) and B. coagulans (3%) were identified from 120 isolates randomly selected from spore count plates of the highest dilution showing growth.     

AQUEOUS GARLIC EXTRACT AND MICROBIOLOGICAL QUALITY OF REFRIGERATED POULTRY MEAT

The antibacterial effect of garlic extract (5, 10 and 15%) was investigated on poultry carcasses obtained from a slaughterhouse, stored under refrigeration, and evaluated at selected time intervals. The effect of the garlic extract on the microbial contaminants of the poultry carcass surface – Salmonella, strict and facultative aerobic, mesophilic, and total and fecal coliforms – was evaluated. The garlic extract exhibited a concentration‐dependent reduction of microbial contamination. Garlic extract concentrations of 10 and 15% were the most effective. The bacteriostatic action of garlic extract against mesophilic microbiota can be observed until the third storage day. The count of total and fecal coliforms remained low during the storage period. Chicken feed was the apparent source of Salmonella contamination, and the aqueous garlic extract was not effective against Salmonella.     

Microbiological quality of fresh pasta dumplings sold in Bologna and the surrounding district

The microbiological quality of fresh pasta dumplings sold in Bologna and the surrounding district was evaluated. A total of 60 lots (300 subsamples) of fresh pasta dumplings, both 'home-made' and manufactured, were analysed for aerobic plate count (APC), coliforms (total and fecal), Staphylococcus aureus, Clostridium perfringens and Salmonella spp. Thirty one of the 39 lots of 'home-made' pasta were found to exceed APC standards and six lots exceeded S. aureus standards. Five (24%) and six (29%) lots of the manufactured pasta were found to be unsatisfactory as regards APC standards and S. aureus standards respectively. The results obtained indicated that a high percentage of samples had a contamination of fecal origin. No Cl. perfringens or Salmonella spp. were found.     

Efficacy of chlorine dioxide gas sachets for enhancing the microbiological quality and safety of blueberries

In response to increasingly stringent microbial specifications being imposed by purchasers of frozen blueberries, chlorine dioxide (ClO2) gas generated by a dry chemical sachet was assessed for inactivation of Listeria monocytogenes, Salmonella spp., and Escherichia coli O157:H7 as well as five yeasts and molds known for blueberry spoilage. Fresh blueberry samples (100 g) were separately inoculated with cocktails of L. monocytogenes, Salmonella, E. coli O157:H7 (three strains each), or yeasts and molds (five strains each) to contain approximately 10(6) CFU/g and exposed to ClO2 (4 mg/liter, 0.16 mg/g) for 12 h in a sealed 20-liter container (99.9% relative humidity) at approximately 22 degrees C. After gassing, 25 g of blueberries was added to 225 ml of neutralizing buffer, pulsified for 1 min, and plated using standard procedures to quantify survivors. This treatment yielded reductions of 3.94, 3.62, 4.25, 3.10, and 3.17 log CFU/g for L. monocytogenes, Salmonella, E. coli O157:H7, yeasts, and molds, respectively. Thereafter, 30 lugs of uninoculated blueberries (approximately 9.1 kg per lug) were stacked on 1.2 by 1.2-m pallets (5 lugs per level x six levels), tarped, and exposed to ClO2 (18 mg/liter, 0.13 mg/g) for 12 h. After gassing, significant (P < 0.05) reductions of 2.33, 1.47, 0.52, 1.63, and 0.48 log CFU/g were seen for mesophilic aerobic bacteria, coliforms, E. coli, yeasts, and molds, respectively, compared with non-gassed controls. No significant differences (P > 0.05) in microbial inactivation were seen between lug levels and, with one exception (mesophilic aerobic bacteria), between the bottom and top surface of individual lugs. Based on these findings, ClO2 sachets may provide a simple, economical, and effective means of enhancing the microbial shelf life and safety of blueberries.     

Microbiological quality of terrestrial gastropods prepared for human consumption

Hygienic quality was investigated in 60 samples of ready-to-eat snails (Helix lactea, Helix nemoralis, and Helix hortensis) obtained from 30 in-season street stalls and 30 catering establishments (bars) in Córdoba. In accordance with Spanish legislation regarding hygiene in the preparation, distribution, and sale of prepared foods, counts were obtained for total mesophilic aerobic bacteria, coliforms, total Enterobacteriaceae, Escherichia coli, Salmonella, and Staphylococcus aureus. The results obtained showed that 33.3, 20.0, and 13.3% of the samples from stalls and 73.3, 53.3, and 6.7% of the samples from bars did not comply with the regulations with respect to the control of total mesophilic aerobic bacteria, Enterobacteriaceae, and Staphylococcus aureus, respectively. Coliforms were found in 53.3% of the samples from the bars (mean, 2.1 CFU/g) and in 33.3% of the stalls (mean, 1.1 CFU/g). Salmonella was not detected.     

Microbiological quality of fresh, minimally-processed fruit and vegetables, and sprouts from retail establishments

A survey of fresh and minimally-processed fruit and vegetables, and sprouts was conducted in several retail establishments in the Lleida area (Catalonia, Spain) during 2005-2006 to determine whether microbial contamination, and in particular potentially pathogenic bacteria, was present under these commodities. A total of 300 samples--including 21 ready-to-eat fruits, 28 whole fresh vegetables, 15 sprout samples and 237 ready-to-eat salads containing from one to six vegetables--were purchased from 4 supermarkets. They were tested for mesophilic and psychrotrophic aerobic counts, yeasts and moulds, lactic acid bacteria, Enterobacteriaceae, presumptive E. coli and Listeria monocytogenes counts as well as for the presence of Salmonella, E. coli O157:H7, Yersinia enterocolitica and thermotolerant Campylobacter. Results for the fresh-cut vegetables that we analyzed showed that, in general, the highest microorganism counts were associated with grated carrot, arugula and spinach (7.8, 7.5 and 7.4 log cfu g(-1) of aerobic mesophilic microorganisms; 6.1, 5.8 and 5.2 log cfu g(-1) of yeast and moulds; 5.9, 4.0 and 5.1 log cfu g(-1) lactic acid bacteria and 6.2, 5.3 and 6.0 log cfu g(-1) of Enterobacteriaceae). The lowest counts were generally associated with fresh-cut endive and lettuce (6.2 and 6.3 log cfu g(-1) of aerobic mesophilic microorganisms; 4.4 and 4.6 log cfu g(-1) of yeast and moulds; 2.7 and 3.8 log cfu g(-1) lactic acid bacteria and 4.8 and 4.4 log cfu g(-1) of Enterobacteriaceae). Counts of psychrotrophic microorganisms were as high as those of mesophilic microorganisms. Microbiological counts for fresh-cut fruit were very low. Sprouts were highly contaminated with mesophilic (7.9 log cfu g(-1)), psychrotrophic microorganisms (7.3 log cfu g(-1)) and Enterobacteriaceae (7.2 log cfu g(-1)) and showed a high incidence of E. coli (40% of samples). Of the samples analyzed, four (1.3%) were Salmonella positive and two (0.7%) harboured L. monocytogenes. None of the samples was positive for E. coli O157:H7, pathogenic Y. enterocolitica or thermotolerant Campylobacter.     

Moulds, yeasts and aerobic plate counts in ginseng supplements

Forty six ginseng supplement samples including Siberian ginseng root, Chinese ginseng herb and root, and American ginseng root and extract were purchased from retail in the Washington, DC area and from Penn Herb Co. (Philadelphia, PA) and tested for mould and yeast (MY) contamination and the presence of aerobic mesophilic bacteria (APC). Results indicated that 100% of the Siberian ginseng samples were contaminated with fungi and bacteria. MY counts ranged from 8.0 x 10(2) to 1.4 x 10(3) cfu/g whereas the APCs were between 2.3 x 10(4) and 1.0 x 10(6) cfu/g. Most common fungi encountered in this commodity were Penicillium spp., Eurotium rubrum, E. chevalieri and Rhizopus spp. Seventy-eight percent of the Chinese ginseng herb samples were contaminated with fungi and 89% with bacteria at levels ranging between <100 and 6.0 x 10(4) and <100 and 1.2 x 10(6) cfu/g, respectively. Moulds commonly isolated were Alternaria alternata, Aspergillus niger, Aspergillus spp., Cladosporium spp., E. chevalieri, Penicillium spp. and Rhizopus spp. Fifty six percent of the Chinese ginseng root samples tested contained fungi (A. niger, Rhizopus spp. and yeasts), and 100% contained bacteria. Fungal counts ranged between <100 and 1.4 x 10(3) cfu/g and APCs were between 3.0 x 10(2) and 6.8 x 10(5) cfu/g. Forty-eight percent of the American ginseng root samples contained moulds and 30% showed bacterial contamination. MY counts were between <100 and 4.3 x 10(5) cfu/g whereas APCs were between <100 and 4.5 x 10(4) cfu/g. A. flavus was isolated from 9% and Penicillium spp. were recovered from 39% of the tested samples. This is the first report of A. flavus contamination in ginseng supplements. No moulds or yeasts were found in ginseng extract, but 50% of these samples contained bacteria at levels ranging between <100 and 1.0 x 10(3) cfu/g.     

自然发酵黄豆酱的微生物安全性的分析

对从11份农家和7份市场上销售的自然发酵黄豆酱样品进行了微生物的安全性检验和部分理化指标的测定，检验的项目包括细菌落总数、芽孢杆菌总数、大肠杆菌、沙门氏菌、志贺氏菌、腊样芽孢杆菌、金黄色葡萄球菌和肉毒梭菌。实验结果表明，所分析样品中菌落总数超过10^4个/g的样品有89％，腊样芽孢杆菌的检出率为30％，但含量不高，豆酱中的细菌总数除了与生产环境有关外，与产品的水分活度的相关性很大。     

Effect of y‐radiation on chives safety and quality

The effect of γ‐irradiation on the quality of chives was evaluated. The samples were irradiated at 1.0 and 2.0 kGy, stored at 4 °C for 10 days and used for microbiological (aerobic mesophilic, moulds and yeasts, E. coli and Salmonella sp), biochemical (vitamin C and lipoperoxide (MDA) contents and superoxide dismutase (SOD) and guaiacol peroxidase (POX) activity) and sensorial evaluation. For irradiated samples, the total counts of aerobic mesophilic and moulds and yeasts showed a reduction of 6 log cycles during storage, and colour analysis showed no significant difference (P > 0.05) for the b*‐value. The contents of vitamin C were not significantly affected by irradiation and storage time. The MDA contents and SOD activity changed insignificantly at both γ‐irradiation levels after storage, while POX was significantly increased (P ≤ 0.05) at 1 kGy. Samples irradiated at 2.0 kGy presented sensorial acceptance after the storage. These results show that γ‐irradiation increases the shelf life of chives without significant changes in their quality.