Unravelling physiological and biochemical attributes influencing post harvest quality of gladiolus spikes after packaging and low temperature storage

The perishable nature of flowers urge for their appropriate post harvest management especially storage and packaging that keep the quality and potential vase life for better value. Gladiolus, commonly called as Sword lily, is a commercially important cut flower crop with elegant spikes, bright florets and good keeping quality. In the present study, we investigated the physiological and biochemical attributes affecting post harvest life of gladiolus spikes after packaging and storage. The spikes of four gladiolus cvs. Punjab Glance, Punjab Glad-1, Punjab Glad-2 and Punjab Pink Elegance were harvested at tight bud stage and packed in PP sleeves (25 ?m) and stored vertically at 4-5°C for 6, 9 and 12 days. After storage, the post harvest quality of both packed and unpacked spikes declined with more adverse effect on unpacked spikes. Among different storage durations, the spikes stored for 9 days showed good keeping quality parameters viz., vase life, per cent flower opened, floret size, days to opening of basal floret, maximum number of florets open at one time and water absorbed per spike which were at par with spikes stored for 6 days. The spikes stored for 12 days were found to be unacceptable in comparison to freshly harvested spikes and spikes stored for 6 and 9 days. The improved quality of spikes stored in sleeves could be accounted due to higher membrane stability index, relative water content, catalase and peroxidase activity as compared to unpacked spikes. Thus, loss in quality of spikes as compared to fresh during storage up to 9 days in PP sleeves is better than the complete loss of produce during transportation and gluts. Hence, the spikes of gladiolus could be stored dry at 4±0.5°C in PP sleeves for 9 days without much influence on its post harvest quality.

Survival of Salmonella spp. in minced meat packaged under vacuum and modified atmosphere

Abstract The effect of different modified atmosphere packaging regimes on the behavior of Salmonella spp. on minced meat was studied. Minced meat was experimentally contaminated with a Salmonella spp. cocktail (S. Enteritidis, S. Typhimurium, S. Infantis and S. Arizonae), packaged under vacuum or modified atmosphere with initial headspaces containing 20%O2/50%CO2/30%N2 and 20%O2/30%CO2/50%N2) and stored at 3 ± 1 °C for 12 days. Samples were analyzed for Salmonella spp., viable and lactic acid bacteria count every third day. Salmonella spp. counts decreased during storage in all packaging types, with reductions of about 1.5 log CFU/g. A significant difference (p < 0.01) was noted between Salmonella spp. counts in meat packaged in vacuum and modified atmospheres, although there was no significant difference in Salmonella spp. count between meat packaged in 50%CO2, and meat packaged in 30%CO2. At the end of the study, there were significant differences (p < 0.01; p < 0.05) in total viable and lactic acid bacterial counts between meat packaged in vacuum and modified atmosphere, and the lowest counts were noted in meat packaged in modified atmosphere with 50%CO2.

Effect of rosemary essential oil and modified-atmosphere packaging (MAP) on meat quality and survival of pathogens in poultry fillets

The effect of rosemary (Rosmarinus officinalis L.) essential oil (REO) and modified-atmosphere packaging (MAP) on the survival of certain pathogens (Salmonella Typhimurium and Listeria monocytogenes) in poultry fillets and on their meat quality during 7 days of refrigerated storage were investigated. Because REO at 0.05% and 0.1% had weak antibacterial activity and REO at 0.3%, 0.5% and 1.0% imparted unacceptable organoleptic properties, only REO at 0.2% was used to treat the poultry meat. The results showed that adding 0.2% REO to poultry fillets did not reduce the size of the population of S. Typhimurium and L. monocytogenes. However, REO treatment significantly decreased the L* (lightness) value and increased the a* (redness) value of stored fillets, and adding REO in combination with MAP reduced the level of lipid oxidation. In conclusion, in a suitable combination, REO can be applied to improve the quality of meat, but further studies should be conducted to determine the appropriate commercial level for different meat products.

Influência do ácido lático e da embalagem em atmosfera modificada sobre a validade comercial da linguiça frescal de frango / Influence of lactic acid and modified atmosphere packing in shelf life of fresh poultry sausage

O objetivo deste trabalho foi caracterizar a influência da embalagem em atmosfera modificada (EAM) e do ácido lático (AL) navalidade comercial da linguiça frescal de frango. Para tanto, foram processadas duas massas de linguiça, sendo uma delasadicionado ácido lático (0,15%). As linguiças foram então embaladas nas seguintes atmosferas: 100%ar atmosférico, 100%N2, 100% CO2, 80% CO2/20% N2, 40% CO2/60% N2 e 20% CO2/80% N2, e armazenadas durante 16 dias a 4±2oC. Foramrealizadas, nos dias 0, 1, 9 e 16, análises bacteriológicas: contagem em placa de bactérias heterotróficas aeróbias mesófilas,bactérias heterotróficas aeróbias psicrotróficas, bactérias ácido-láticas, enterobactérias e Pseudomonas; e determinaçãodo pH. A EAM a 80/20 CO2/N2 mostrou-se como método mais eficaz, sob o ponto de vista microbiológico, em termos deconservação da linguiça frescal de frango, atingindo ao final do experimento valores de 6,0; 5,3 e 5,0 Log UFC/g (bactériasmesófilas, psicrotróficas e ácido-láticas, respectivamente). Em relação à adição do AL, tal tratamento foi eficaz sob o aspectode inibição microbiológica em quase todas as atmosferas, com exceção da 80/20 CO2/N2. Durante o experimento, não foiobservado crescimento de enterobactérias e Pseudomonas. Em relação ao pH, pôde-se observar que a adição de 0,15% deAL provocou uma queda do pH de 5,89 para ~5,50, suficiente para acarretar uma inibição significativa da taxa de multiplicaçãomicrobiana nas diferentes atmosferas, exceto na 80/20 CO2/N2. Pôde se concluir que a EAM com 80/20 CO2/N2, mostrou-secomo o método de conservação mais eficaz quanto ao aumento da vida útil da linguiça de frango e a adição de 0,15% de ALdemonstrou ser uma alternativa eficaz para conservação deste produto.

The present work has an objective to observe and to characterize, through microbiological analyses and pH determination, the influence of the Modified Atmosphere Packaging (MAP) and the lactic acid addictive in shelf life of fresh poultry sausage. Two sausage batches were made under laboratory control. One of them was added of lactic acid (0.15%). The samples were processed, and packaged in plastic bags (four sausages per bag). Finally, the bags were filled with different atmospheres: 100% air, 100% N2, 100% CO2, 80/20 CO2/N2, 40/60 CO2/N2 and 20/80 CO2/N2. Samples were stored in walk?in cold rooms at 4±2°C. Samples were taken at different days of storage (zero, 1, 9 and 16). Both added and not added with lactic acid samples were subjected to total viable aerobic counts (mesophylic and psycrophylic), lactic acid bacteria, Enterobacteriaceae, and Pseudomonas sp. in specific media plates. Also, it was determinate the pH of all the samples. The results were arranged in tables and graphs for the descriptive statistical analyses. The MAP 80/20 CO2/N2 was the more effective method to conserve fresh poultry sausages, reaching at the end of the experiment values of 6.0; 5,3 and 5.0 Log UFC/g (mesophylic, psycrophylic and acid-lactic bacteria, respectively), comparing to the conventional package (100% air) and 100% N2 that reached at the end of the experiment maximum values of 8.8 and 9.4 Log UFC/g, respectively. The addition of the acid lactic was effective about the aspect of microbiological inhibition, reaching inferior values in almost all the atmospheres comparing to the samples without addition of the acid, except to 80/20 CO2/N2, that the values of the microbial count in both treatments (with and without acid) they were very close. During the experiment, it was not observed the growth of Enterobacteriaceae and Pseudomonas. Analyzing the pH, it can be observed that the addition of 0.15% lactic acid caused a fall of the pH of 5.89 for ~5.50, enough to inhibit the microbial multiplication in the different atmospheres, except in 80/20 CO2/N2. After analyzed this results, it was concluded that MAP to 80/20% of CO2/N2 was the more effective method to increase the shelf life of the fresh poultry sausage, added or not added with lactic acid; the addition of 0.15% of lactic acid was an effective alternative for conservation of fresh poultry sausage chicken, wrapped or not in modified atmosphere