chilling period
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2021 ◽  
Vol 2 (3) ◽  
pp. 26-32
Author(s):  
Saeed Mohammad Weqar

Liver is chemically complex matrixes contain sufficient nutrients that support microbial growth. Microbial contamination of vending chicken livers could occur due to different possible reasons such as storing foods in cheap utensils, holding foods at a temperature that would permit bacterial growth, utilization of water of questionable hygienic quality, using packing materials that were not of food-grade quality, vending site that has no facilities for waste disposal and utilization of unclean utensils. In addition, street chicken livers vendors are unaware of the basic importance of personal cleanliness, thus their products are usually vulnerable to gross contamination by flies, insects, rodents, dust and other dirt. Vending chicken livers are often poor and uneducated and lack appreciation for safe food handling. Aim of the study is to determine microbiological quality of chicken livers in Jalalabad city.  A total of 24 samples of vender chicken livers   from 4 different shops had purchased from Jalalabad city Afghanistan. This step occurred earlier than the chilling period then Transfer Directly to the Microbiological laboratory of Veterinary Science faculty of Nangarhar University for Microbial culture and microscopic examination.   According to our study we have seen 6 (25%) samples positive for Salmonella and 24(100%) samples positive for Shigella. Studies made in Nangarhar pointed out that the important aspect of vending chicken livers is their safety and understanding the possible ways of contamination. The sanitary condition need to be improved.  The government must develop microbiological standards of fast food and urgently put them in practice.


Author(s):  
Marie-Pierre Fortier ◽  
Frédéric Guay ◽  
Linda Saucier

Oregano oil and cranberry pulp supplements were added to the diets of finishing pigs to determine their effects on meat quality of fresh loins during storage. Two and three levels of oregano oil (250 and 500 mg kg-1) and cranberry pulp (5, 10 and 20 g kg-1) were tested, according to a factorial experimental design. The loin meat was vacuum-packed and analysed at 0 (after the 24-h chilling period post slaughter), 23, 45 and 60 days of storage. Samples were repackaged under aerobic conditions after 0 or 23 days and analysed after 4, 8 and 12 days. Oregano and cranberry supplements did not affect lipid oxidation (µg of MDA equivalent per kg of meat) during anaerobic or aerobic storage. On day 0, the fatty acid profile of the loin samples demonstrated that the addition of cranberries at a dose of 10 g kg-1 was associated with a lower percentage of saturated fatty acids (P = 0.04; 42.97% vs. 40.99%) and trend for a higher percentage of monounsaturated fatty acids (P = 0.06; 47.26% vs. 46.09%). Considering the result obtained, feeding pigs with oregano and cranberry supplements had a limited effect on meat quality parameters measured during storage.


Foods ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1333
Author(s):  
Santiago P. Aubourg ◽  
Marcos Trigo ◽  
Beatriz Martínez ◽  
Alicia Rodríguez

The effect of a prior chilling period and an alga extract packaging on the quality of a canned underutilised mackerel species (Scomber colias) was investigated. For this different chilling times (0, 4 and 9 days) were taken into account and three concentrations of aqueous extracts of the macroalga Fucus spiralis were tested in a brine-packaging medium. Chemical changes related to quality were analysed after 3 months of canned storage. A substantial increase (p < 0.05) in free fatty acid content was observed in canned fish by increasing the chilling time; however, alga extract presence in the packaging medium led to decreased mean values. Concerning lipid oxidation development, an increased chilling time led to higher values (p < 0.05) of thiobarbituric acid index and fluorescent compounds formation; remarkably, an increased presence of alga extract led to a higher (p < 0.05) peroxide retention and lower (p < 0.05) fluorescent compounds content. Average colour L* and a* values showed a decrease and an increase, respectively, with chilling time; however, such changes were minimised with the alga extract content in the packaging system. Trimethylamine content revealed a marked increase as a result of the sterilisation step, but no influence (p > 0.05) of the chilling time or the alga-packaging medium could be implied.


Foods ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1017 ◽  
Author(s):  
Ebeed Saleh ◽  
Alaa Eldin Morshdy ◽  
Eman El-Manakhly ◽  
Sarah Al-Rashed ◽  
Helal F. Hetta ◽  
...  

Poultry meat is commonly marketed at refrigerated temperatures (2–5 °C). The major concern for retailers and consumers is the quality and safety of refrigerated poultry meat. During the chilling period, poultry meat undergoes too many undesirable changes due to microbial growth that leads to spoilage and economic loss. Therefore, this study was conducted to assess the effects of olive leaf extracts (OLE) used at three concentrations (0.25, 0.5, and 1%) on the sensory attributes, as well as the chemical and microbiological quality of raw poultry meat stored at 4 ± 1 °C for 15 days. The results revealed that the OLE addition reduced microbial growth successfully, and maintained the chemical quality and sensory attributes of poultry meat. Moreover, OLE extended the shelf-life of the poultry meat that held under proper refrigeration conditions up to 15 days compared to the control group, that was completely spoiled by the sixth day of storage. This study concludes that OLE could be used both as a natural antioxidant and an antimicrobial preservative for chilled poultry meat held at refrigerated temperature.


2020 ◽  
Vol 110 (5) ◽  
pp. 588-596
Author(s):  
Cleopatra A. Moraiti ◽  
Kirsten Köppler ◽  
Heidrun Vogt ◽  
Nikos T. Papadopoulos

AbstractThe European cherry fruit fly, Rhagoletis cerasi (Diptera: Tephritidae), is a univoltine species that undergoes obligatory summer–winter diapause at pupal stage in the soil (2–5 cm) beneath host trees. To study the effects of photoperiod and relative humidity on diapause termination and post-winter developmental duration of R. cerasi, pupae collected from Dossenheim (Germany) were exposed to different photoperiod or relative humidity regimes during a chilling period ranging from 2 to 8.5 months. Specifically, pupae were exposed to four photoperiod regimes: (a) light conditions (24L:00D), (b) dark conditions (00L:24D), (c) short photoperiod (08L:16D) and (d) long photoperiod (16L:08D), as well as to three relative humidity regimes: (a) low (40% RH), (b) medium (60% RH) and (c) high (70–80% RH). Data revealed that relative humidity is not a significant predictor of diapause termination, but it affects the post-winter developmental period. Higher relative humidity promotes post-winter pupae development. On the other hand, photoperiod significantly affected both diapause termination and post-winter development of R. cerasi pupae. Light conditions (24L:00D) accelerate adult emergence, particularly for females. Regardless of the photoperiod (24L:00D, 00L:24D, 08L:16D), rates of adult emergence were high (>75%) for chilling intervals longer than 6.5 months. Nonetheless, exposure to a long day photoperiod (16L:08D), during chilling, dramatically reduced the proportion of adult emergence following 6 months exposure to chilling. Our findings broaden the understanding of factors regulating diapause responses in European cherry fruit fly, local adaptation and synchronization of adult emergence with the ripening period of major hosts.


Agronomy ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 73 ◽  
Author(s):  
Bianca Drepper ◽  
Anne Gobin ◽  
Serge Remy ◽  
Jos Van Orshoven

Based on observations for the beginning of the flowering stage of Malus domestica (apple) and Pyrus communis (pear) for the 1950–2018 period, phenological trends in north-eastern Belgium were investigated in function of temperatures during dormancy. Moreover, two different phenological models were adapted and evaluated. Median flowering dates of apple were on average 9.5 days earlier following warm dormancy periods, and 11.5 days for pear, but the relationship between bloom date and temperature was found not to be linear, suggesting delayed fulfilment of dormancy requirements due to increased temperatures during the chilling period. After warm chilling periods, an average delay of 5.0 and 10.6 days in the occurrence date of dormancy break was predicted by the phenological models while the PLSR reveals mixed signals regarding the beginning of flowering. Our results suggest overlapping chilling and forcing processes in a transition phase. Regarding the beginning of flowering, a dynamic chill model coupled to a growing degree days estimation yielded significantly lower prediction errors (on average 5.0 days) than a continuous chill-forcing model (6.0 days), at 99% confidence level. Model performance was sensitive to the applied parametrization method and limitations for the application of both models outside the past temperature ranges became apparent.


2019 ◽  
Vol 78 (2) ◽  
pp. 107-115
Author(s):  
Nina Šajna ◽  
Mirjana Šipek ◽  
Jelka Šuštar-Vozlič ◽  
Mitja Kaligarič

Abstract The present-day diversity of European flora in temperate mountain ranges was mainly formed by the negative effects of Pleistocene glaciation, which caused extinctions, restricted survival in situ, and subsequent re-colonization. Only rarely can we find species that have retained the molecular information of in situ survival. One such example is the extremely rare H. pastinacifolia Rchb., a monotypic genus and a narrow endemic of a mountain plateau south-east of the Julian Alps (Slovenia). We investigated the germination behavior and dispersal indications, which are often closely related to rarity and persistence and thus valuable for species conservation. Additionally, results about H. pastinacifolia help us to understand better what kind of species survived glaciations in Europe in situ. Our results show that these seeds have an underdeveloped embryo and require an ecologically relevant moist chilling period of about 100 days. The temperature sequence of the colder period that H. pastinacifolia seeds received in nature was 20/15 °C (52 days), 10/5 °C (40 days), 5/0 °C (65 days), 10/0 °C (45 days), 15/5 °C (21 days). The germination rate was high, significantly increased by scarification, and therefore prevented long-term seed bank establishment. We found cryptic seed differences expressed by two types of dormancy, each related to the order of the umbel: simple and complex morphophysiological dormancy for the lateral and the main umbel, respectively. Seed dispersal was very much influenced by precipitation in autumn. The germination and dispersal characteristics could explain the rarity and at the same time the persistence of H. pastinacifolia.


2018 ◽  
Author(s):  
Souleymane Diallo ◽  
Momar Talla Seck ◽  
Jean Baptiste Rayaissé ◽  
Assane Gueye Fall ◽  
Mireille Djimangali Bassene ◽  
...  

Background The sterile insect technique (SIT) requires mass-rearing of the target species, irradiation to induce sexual sterility and transportation from the mass-rearing facility to the target site. Those treatments require several steps that may affect the biological quality of sterile males. This study has been carried out to evaluate the relative impact of the chilling, irradiation and transport on emergence rate, flight ability and survival of sterile male tsetse flies Glossina palpalis gambiensis. Results Chilling, irradiation and transport all affected the quality control parameters studied. The emergence rate was significantly reduced by long chilling periods and transport, i.e. from 92% at the source insectary to 78% upon arrival in Dakar. Flight ability was affected by all three parameters with 31% operational flies lossed between the source and arrival insectaries. Only survival under stress was not affected by any of the treatments. Conclusion The chilling period and transport were the main treatments which impacted significantly the quality of sterile male pupae. Therefore, the delivery of sterile males was divided over two shipments per week in order to reduce the chilling time and improve the quality of the sterile males. Quality of the male pupae may further be improved by reducing the transport time and vibration during transport. Keys words: Tsetse flies, mass-rearing conditions, sterile insect technique, quality


2018 ◽  
Vol 26 (2) ◽  
pp. 25-35
Author(s):  
Isam A.H. Al-Madhagi ◽  
Mahassen Al-Munibary ◽  
Manssur Al-Doubibi

AbstractThe influence of chilling period hours and accumulative photo-thermal unit at different base temperatures, 10, 11, 13, 15, and 18 °C, on the flowering of strawberry was examined in Sana’a University-Yemen during two seasons: 2006 and 2007. The randomized complete block design (RCBD) field experiment was designed with 5 chilling hours (CHs) periods (0, 360, 750, 1080, and 1440 CHs under 2 ± 1 °C), with four replicates each. Accumulative photo-thermal unit (PTU) was calculated for every treatment at different base temperatures for two stages: (i) from planting date to the flower opening (THA) and (ii) from planting date until the end of 2 months (THB). The results revealed that the plants treated with 1080 h of chilling produced flowers with about 55.12% and 61.97% earlier when compared with control (without chilling) in both the seasons, respectively. Stepwise multiple regression analysis showed that both CHs and the accumulative PTU THA13 (in the first season) and CH plus THA10 (in the second season) have significant effect on days until flower opening, in which the majority effect was related to the chilling period. The effect of chilling period and accumulative PTU at 18 °C (THB18) had s significant influence (p < 0.05) on the number of early flower per plant, with about r2 = 0.250 and r2 = 0.536 in both the seasons, respectively, and r2 = 0.531 and r2 =0.740 for the total effect of both CH and THB18, respectively. However, the exposure of plants to the long period of chilling (1080 and 1440 h) led the plants to produce runners and break up the flowering stage after 9 and 11 weeks in both the seasons, respectively. Meanwhile, plants that received 360-h chilling produced significantly highest (p < 0.05) total number of flowers (24.83 per plant), with about 71.2% higher than that produced by control plants. Moreover, in the second season, plants treated with 750-h chilling produced the significantly higher total number of flowers per plant, with about 50.3% higher than that of the control. Meanwhile, the 360-h and 750-h chilling periods have similar effect on the number of flowers per plant in the second season. The result showed that the starch level in the crown significantly positively correlated with the days to flower opening (r2 = 0.415, p = 0.05) and negatively correlated with the number of early flower (r2 = 0.587, p = 0.01). The data from this study might be used for the management of strawberry production.


2018 ◽  
Vol 14 (8) ◽  
pp. 20180277 ◽  
Author(s):  
Yin Wen ◽  
De-wen Qin ◽  
Bing Leng ◽  
Yun-fei Zhu ◽  
Kun-fang Cao

Plants are moving poleward and upward in response to climate warming. However, such movements lag behind the expanding warming front for many reasons, including the impediment of plant movement caused by unusual cold events. In this study, we measured the maximum photochemical efficiency of photosystem II ( F v /F m ) in 101 warm-climate angiosperm species to assess their cold tolerance at the end of a severe chilling period of 49 days in a southern subtropical region (Nanning) in China. We found that 36 of the 101 species suffered from chilling-induced physiological injury, with predawn F v /F m values of less than 0.7. There was a significant exponential relationship between the predawn F v /F m and northern latitudinal limit of a species; species with a lower latitudinal limit suffered more. Our results suggest that the range limits of warm-climate plants are potentially influenced by their physiological sensitivity to chilling temperatures and that their poleward movement might be impeded by extreme cold events. The quick measurement of F v /F m is useful for assessing the cold tolerance of plants, providing valuable information for modelling species range shifts under changing climate conditions and species selection for horticultural management and urban landscape design.


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