Days Of Cold Storage Research Articles

Structural and sensory analysis of compositionally optimized apple jellies enriched with dietary fibre compared to commercial apple jams.

The objective of this work was to optimize the formulation of apple jellies enriched with 3g/100g of dietary fibre and to compare them with commercial apple jams in terms of structural and organoleptic properties. With that aim, a fibre mix with one part of psyllium and three parts of other fibre variety (apple, bamboo or wheat) was added to apple jelly, and the rheological, mechanical and sensory properties, as well as colour and syneresis (water loss) of the samples at different storage times were studied, and compared to two commercial apple jams. Those properties did not suffer significant changes during 30days of cold storage, meaning that the product was stable. The reduction of psyllium proportion in the fibre mix (from 1:1 to 1:3) reduced the gumminess of the fibre enriched jellies, keeping the syneresis at 0g/100g. The jelly enriched with apple and psyllium fibre was the most similar to commercial apple jams in terms of rheological and mechanical properties. Consumers acceptability of fibre enriched jellies was higher than 72%, being the jelly enriched with bamboo and psyllium fibre the closest to a commercial apple jam, which was the consumer's favourite.

Impact of Fluoridation of Milk on Manufacturing and Properties of Yoghurt

Fluoridation ( F ) of yoghurt milk ( YM ) was done by adding sodium fluoride to YM before ( treatment A ) and after ( treatment B ) the heat treatment applied on cow's milk . Activity of yoghurt starter culture (YSC) was followed during fermentation by measuring acidity and pH at different intervals up to the complete coagulation. The resultant control (C) and treated yoghurt were analysed when fresh and after 10 days of cold storage (5 ± 1 ⁰C).The attained results revealed that F had no pronounced impact on YSC, while the differences in acidity, pH, TS, fat and protein contents of the resultant yoghurt due to the applied treatments were slight. Curd syneresis (CS) of C kept for 10 and 30 min at room temperature (30 ± 1 ⁰C) was higher than the corresponding treated samples, while after 60 and 90 min the differences in CS were slight in fresh samples. The stored samples showed opposite trend of results. F of YM had no obvious impact on hardness, springiness and gumminess of yoghurt. Adhesiveness was higher in C, while the opposite was noticed for cohesiveness.Organoleptically, the fresh treated yoghurt ranked less scores for appearance and firmness while some improvement was recorded during storage of all samples. No adverse impact of F was noticed on flavour attributes.

Control of Gray Mold on Clamshell-Packaged 'Benitaka' Table Grapes Using Sulphur Dioxide Pads and Perforated Liners.

The use of vented clamshells has become popular in the packaging of grapes for local and international markets. The aim of this study is to evaluate the postharvest preservation of ‘Benitaka’ table grapes individually packaged in vented clamshells using different types of SO2-generating pads and perforated plastic liners during cold storage. A completely randomized design with four replications in a two-factor arrangement with an additional treatment [(4 × 3) + 1] was used. The trials were carried out under two situations: Artificial or natural infections with Botrytis cinerea, which is the causal agent of gray mold on table grapes. The incidence of gray mold, shattered berries, and stem browning were evaluated at 30 and 45 days of cold storage at 1 ± 1 °C and 3 days of shelf-life at 22 ± 1 °C after the period of cold storage. Mass loss and berry firmness were also examined at the end of the cold storage period. The use of dual-release SO2-generating pads containing 5 or 8 g of a.i. and slow-release pads with 7 g of a.i. was effective in controlling the incidence of gray mold in grapes packaged in vented clamshells and kept under cold storage for up to 45 days. Under these storage conditions, perforated plastic liners with 0.3% ventilation area or micro-perforated liners with 1.0% ventilation area reduced the percentage of mass loss and shattered berries.

EVALUATION OF PHYSICO-CHEMICAL PROPERTIES AND ANTIOXIDANT ACTIVITY OF STIRRED YOGHURT FORTIFIED WITH POMEGRANATE AND CACTUS PEAR JUICES

This study was carried out to estimate the effect of adding pomegranate (Punica granatum L) and cactus pear (Opuntia ficus indica) juices as natural ingredients on physico-chemical characteristics, antioxidant activity, microbiological examination and sensory evaluation of stirred yoghurt. Stirred yoghurt was prepared by using cow, s milk 3% fat, and pomegranate and cactus pear juices were added at the rate of 5%, 10% and 15% W/W. All treatments were inoculated with 2% of yoghurt starter and stored at 5°C up to the end of storage period (15 days) after complete a sulation. Physico-chemical properties of yoghurt samples such as total solids, protein, fat, pH, syneresis, viscosity was carried out .Also, microbiological examination and sensory evaluation were determined of all the treatments when fresh ,and then after 5, 10 and 15 days of cold storage at 5°C. The results showed that significant differences were found between the control and stirred yoghurt fortified with juices in the total solids, protein content, pH and titratable acidity up to the end of storage period(15 days). Addition of pomegranate and cactus pear juices led to significant increase in phenolic compounds and antioxidant activity of yoghurt treatments compared with the control sample. In all samples, it was observed that the titratable acidity increased over the storage period. Low values for viscosity and high values for syneresis were belonged to yoghurt containing 15% pomegranate and cactus pear juices. Sensory evaluation results showed that there were significant differences among the yoghurt samples. Stirred yoghurt (control) and stirred yoghurt containing 5% cactus pear or pomegranate juices gained significantly highest flavour and texture scores compared to stirred yoghurt treated with 10% or 15% juices. The results of current study demonstrated that the addition of juices from pomegranate and cactus pear to stirred yoghurt milk, significantly improved the quality of yoghurt and will increase its healthy benefits.

Production of vegetable yoghurt like from lupin milk

The objective of the present study was to produce vegetable milk from lupine seeds as an alternative to natural milk in the yogurt like production. Lupine yoghurt like was made from in-permeate lupine extract fortified with different levels of milk protein concentrate (MPC) powder in comparison with cow-milk yoghurt. Where lupine milk was extracted from soaked legume lupine (Lupinus angustifolius) seeds using milk permeate (1Kg beans / 5 Kg permeate) and divided into 4 equal portions and fortified with MPC powder at level of nil, 1, 2 or 3%. All treatments were converted into yoghurt using 3% bacterial starter culture of Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus (1:1). The results showed that, the addition of MPC to lupine extract led to increase in the total solids content of resultant yoghourts like. Also, cow yoghourt had significantly higher fat content than lupine yoghurt like. Adding MPC to the lupine yoghurt milk resulted in lower fat content. Cow yoghurt had lowest protein content while lupine yoghurt with 3% MPC showed the highest protein content. Crude fiber content of lupine yoghurt without MPC was found to be highest than other yoghurt treatments. Values of viscosity were increased more with ascending ratios of MPC in Lupine milk. Hardness and springiness values of all lupine yoghurt treatments were increased during cold storage and the increase in these two texture parameters were positively correlated to the MPC level. Str. theromphillus or Lb. delbrueckii ssp. bulgaricus count in yoghurt made from cow milk showed higher counts than that of lupine-milk yoghurt like. All samples were free from any contamination either with yeast or fungi organism whether when fresh or after 7 days of cold storage while they appeared after 14 days. All yoghurt were sensory acceptable especially that fortified with 3% MPC powder, which helped to beany flavor disappearing.

Influence of different cold storage times on quality of “Cuiguan” pear fruits during shelf life

This study investigates the effects of different cold storage times (30 days—CS-30d, 40 days—CS-40d, and 50 days—CS-50d) on quality of “Cuiguan” pear fruits during shelf life. The data showed that, compared with 0 days of cold storage, the weight loss and rot rate of the fruit on the shelf increased, the hardness and nutritional quality of the fruit decreased rapidly, and the deterioration rate of the fruit was aggravated. By comparing the quality changes of three storage periods fruits during the shelf life at room temperature, it was found that the longer the refrigeration time was, the faster the quality of “Cuiguan” pear fruit declined in the later shelf life, and the easier the fruit deteriorated. Principal component analysis showed that the quality of Cuiguan pear fruits of CS-50d deteriorated fastest during shelf life at room temperature, followed by fruits stored for CS-40d and CS-30d. This provides a theoretical basis for selecting the cold storage time of “Cuiguan” pear. Practical applications At present, the effect of the refrigeration time of Cuiguan pear on the shelf at room temperature has not been reported. By comparing the changes of fruit quality during shelf life after different cold storage time (30, 40, and 50 days), the optimum cold storage time for Cuiguan pear was 30 days. It prolong the fruit duration and ensured that the fruit quality maintained a high level during shelf life at room temperature.

Influence of carboxy methylcellulose, chitosan and beeswax coatings on cold storage life and quality of Kinnow mandarin fruit

Edible coatings are safer for human health and environment compared to synthetic waxes. The aim of this study was to assess the influence of different edible coatings on extending cold storage life and maintaining fruit quality of ‘Kinnow’ mandarin (Citrus nobilis L. x Citrus deliciosa L.). Kinnow fruit coating treatments included 1.0, 1.5 and 2.0 g L−1 carboxy methylcellulose (CMC), 0.5, 1.0 and 1.5 g L−1 chitosan and 5, 10 and 15 g L−1 beeswax were contrasted to the uncoated (control) fruit. The coated and uncoated fruit were kept under cold storage conditions (5–7 °C and 90–95% RH) up to 75 days. The fruit were sampled following 30, 45, 60 and 75 days cold storage and evaluated for different quality parameters and scanning electron microscopy of the peel surface. The results indicate variability among the different polymer coatings for weight loss, spoilage loss, juice content, firmness, pectin content, the activity of pectin methylesterase and cellulase, soluble solids concentration (SSC), titratable acidity (TA), ascorbic acid content, total carotenoids content and organoleptic sensory attributes. Improved fruit gloss was observed in all coatings treatments, however, with the extension of the cold storage period, the fruit coated with chitosan and beeswax showed outward ruptures on the rind. Amongst all, the coatings tested, CMC (2.0 g L-1) coating was the most effective in maintaining various fruit quality parameters such as SSC, TA, vitamin C, sensory attributes and retarding the activities of cell wall degrading enzymes such as pectin methylesterase and cellulase up to 60 days in cold storage.

Mild heat treatments before minimal processing reduce browning susceptibility and increase total phenolic content of low‐chill apple cultivars

Three low‐chill apple cultivars (“Caricia,” “Eva,” and “Princesa”) were subjected to hot water treatments as a postharvest abiotic stress for quality retention. The effects of heating time and temperature, storage time, and apple cultivar were investigated on total phenolic content (TPC), firmness, color and polyphenol oxidase (PPO), and peroxidase (POD) activities. Apples were heat treated in water at 40–50°C for 20–90 min, stored at 2°C during 24 hr, and minimally processed. Samples were analyzed immediately and after 7 days at 2°C. Apple cultivar and storage time significantly affected the evaluated attributes. Heat treatments did not improve the firmness, color, or TPC of “Caricia” and “Princesa.” While in “Eva” heat treatments increased TPC by 70%, reduced PPO and POD activities and prevented browning development, after 7 days. In conclusion, mild heat treatments could improve the quality and bioactive compound content of low‐chill fresh‐cut apples. Nevertheless, the different responses among cultivars should be accounted for. PRACTICAL APPLICATIONS: The three low‐chill apple cultivars, “Caricia,” “Eva,” and “Princesa,” showed varying responses toward postharvest heat treatment. The TPC of the three studied cultivars was increased by the heat treatment at the minimal processing day. The application of mild heat treatments before minimal processing proved to be an effective postharvest tool to delay enzymatic browning and increase TPC of fresh‐cut “Eva” apples, after 7 days of cold storage.

Combined Effects of Vacuum Packaging and an Active Packaging Based on Whey Protein on Maintaining Quality of Pike–Perch Fillets During Refrigerated Storage (4 °C)

Effects of vacuum packaging (VP) and lactoperoxidase system–whey protein coating (LPOS + WPS) combination on maintaining quality of Pike–Perch fillets during 16 days of cold storage (4 ℃) were studied. Quality assessment was based on microbial (total viable counts, psychrotrophic bacteria, and H2S producing bacteria), chemical (TVBN, TBARS, and pH), and sensory (odor, color, texture, and overall acceptability) analysis. Results of microbial analysis showed significantly (P < 0.05) lower bacterial load in WPS + LPOS + VP than other groups, while highest bacterial load observed in WPS. Similarly, bacterial count, and lowest and highest amount of total volatile basic nitrogen (TVBN) observed in WPS + LPOS + VP and WPS, respectively. Thiobarbituric acid reactive substances (TBARS) values assessment showed that lipid oxidation in WPS + LPOS + VP was significantly (P < 0.05) lower than other groups, while in WPS was highest. Combined VP and WPS + LPOS could maintain the stability of initial pH during cold storage. Sensory results indicated that the shelf-life of Pike–Perch fillets in WPS, WPS + LPOS, WPS + VP, and WPS + LPOS + VP were at least 4, 8, 4, and 16 days, respectively. The results suggested that combined VP and LPOS + WPS can be recommended to extend shelf-life of fish in cold storage. This strategy would be beneficial to the fishery industry as well as the retail market and consumer.

Ultrases Yıkama İşleminin Taze Çileklerin Soğukta Depolama Esnasında Kalite Özelliklerine Etkisi

Çilek karakteristik özellikleri ile tüm dünyada en çok tercih edilen meyveler arasında yer almaktadır. Taze çileğin morfolojik yapısı gereği hasat işleminden sonra soğukta depolama esnasında üründe kalite kayıpları gözlenmektedir. Bu nedenle, taze çileklerde yıkama işlemi özellikle mikrobiyal yükün azaltılması ve raf ömrünün artırılması adına önem arz etmektedir. Tüketici kaynaklı sağlık endişelerinden dolayı meyve ve sebzelerin endüstriyel yıkama işleminde kimyasal kullanımına alternatif olarak geliştirilen yöntemlere talep giderek artmaktadır. Ultrases yıkama, kimyasal yıkama işlemlerine kıyasla mikrobiyal yükün azaltılmasının yanında kalite özelliklerinin korunması açısından tercih edilmeye başlanan yenilikçi bir yöntem olarak karşımıza çıkmaktadır. Bu çalışma kapsamında hasat sonrasında taze çileklere ultrases (550 W/35 kHz) ve peroksiasetik asit (40 ppm) ile yıkama işlemleri uygulanmıştır. Yıkama işlemleri gerçekleştirilen çileklere soğukta depolama esnasında 14 gün boyunca pH, toplam asitlik, suda çözünür kuru madde (briks), C vitamini, toplam fenolik madde, antioksidan kapasite, toplam canlı mikroorganizma, küf ve maya sayısı analizleri uygulanmıştır. Ultrases yıkamanın, kavitasyon etkisi sayesinde çileklerde mikrobiyal yükün azaltılması ve biyoaktif özelliklerin korunumunda diğer yönteme kıyasla daha etkili olduğu belirlenmiştir.

Production of low-fat white soft cheese using sodium caseinate and / or butter milk powder as a fat replacer

The purpose of this study is to improve texture, flavor and overall quality of low-fat white soft cheese. Using sodium caseinate (SC) and / or butter milk powder (BMP) in different ratios. Buffalo’s milk was divided into two portions. The first portion was standardized to 3% fat and served as a control (1). The second portion was standardized to 1% fat and sub divided into five parts, the first part was served as control (2), the second part fortified with 2% SC (T1), the third part fortified with 2% BMP (T2), forth part fortified with 1% SC + 1% BMP (T3) and fifth part fortified with 0.5% SC + 1.5% BMP (T4). All cheese treatments stored in salted whey (5% NaCl) at 5±2°C up to 3 months. The results indicated that, control (2) had obviously lower moisture content than control (1). Addition of sodium caseinate and / or butter milk powder to cheese milk led to an increase in moisture content of resultant cheese compared to control (2). A slight increase was observed in total nitrogen % of low-fat all soft cheese treatments versus control (2) being more obvious in T2 and T3. Low-fat soft cheese treatments were characterized by higher soluble nitrogen % than control (2). Moreover, the results showed also that, replacing of milk fat with SC + BMP caused a decrease in hardness, adhesiveness, springiness, chewiness and gumminess in fresh cheese compared to control (2). Sensory properties of Low-fat soft cheese were highly improved by adding SC + BMP to cheese milk as a fat replacer. Low-fat soft cheese was most preferable in T3 with adding SC + BMP (1:1), those improved the compositional as well as the organoleptical properties, especially its body and texture of low fat brined soft cheese after 90 days of cold storage.

Probiotic Potential of Noni and Mulberry Juice Fermented with Lactic Acid Bacteria

The present study assesses the feasibility of noni and mulberry as a raw substrate for the production of probiotic noni and mulberry juice by lactic acid bacteria (Lactobacillus plantarum SK-3 and Pediococcus acidilactici M-3). Changes in pH, titratable acidity (lactic acid), cell survival, and antioxidant properties were examined during fermentation. Both the strains grew well in noni juice and mulberry juice after 48 hour fermentation. P. acidilactici M-3 produced less lactic acid than L. plantarum SK-3. After 28 days of cold storage, both tested strains survived the low-pH conditions in fermented noni juice and mulberry juice. Both the juices fermented with L. plantarum SK-3 had a high antioxidant capacity. The noni and mulberry juice fermented with L. plantarum SK-3 had shown the cholesterol-lowering ability better than the juices fermented with P. acidilactici M-3. Finally, L. plantarum SK-3 and P. acidilactici M-3 were found as optimal probiotics for fermentation with noni juice as well as mulberry juice. In this investigation, the results could be an indicator of the development of health-promoting food juices.

Botrytis cinerea response to pulsed light: Cultivability, physiological state, ultrastructure and growth ability on strawberry fruit

Botrytis cinerea causes postharvest spoilage in important crops such as strawberry and other berries. Pulsed light (PL) treatment could be an environmentally friendly postharvest alternative to synthetic fungicides in berries. Cultivability, physiological state, ultrastructure of Botrytis cinerea suspended in peptone water and irradiated with PL (fluence = 1.2 to 47.8 J/cm2) were investigated by using conventional plate count technique, flow cytometry analysis (FCM) and transmission electron microscopy. In addition, PL effect on B. cinerea development in artificially contaminated strawberries throughout storage at (5 ± 1) °C was evaluated.PL reduced fungus' ability to form colonies on agarized culture media. Survival curve fitted with the Weibullian model evidenced a wide distribution of conidia sensitivity to PL. FCM showed that most of irradiated conidia entered in a viable non-culturable state, although a subpopulation without esterase activity and compromised membranes and a subpopulation with active esterase and intact membranes were also detected. PL attacked multiple targets in B. cinerea. Ultrastructural changes varied with the dose and within the conidia population, supporting FCM results. Damage included plasmalemma detachment from cell wall, cytoplasm collapse, and vacuolization of cytoplasm, disruption of cell wall and plasmalemma with massive loss of cytoplasm and/or disruption of organelles. In strawberries artificially contaminated with B. cinerea, a 2-day delay on the onset of the infection and a lower incidence in PL-treated strawberries (11.9 and 23.9 J/cm2) compared to control (16–20%) up to 10 days of cold storage was observed. Results indicated that PL significantly reduces B. cinerea growth in peptone water and in inoculated strawberries. However, other preservation factor(s) in combination would be needed to increase PL action for a better control of this fungus.

Application of cultivable lactic acid bacteria isolated from Iranian traditional dairy products for the production of liquid and dried kashks

This study was aimed to produce liquid and dried kashk as a traditional dairy-based product on an industrial scale. Furthermore, the microbial, chemical properties as well as the proximate composition including pH, moisture, salt, fat, protein, total volatile nitrogen (TVN) and peroxide value (PV) were assessed after 1, 10 and 20 days of cold storage (7 °C). Also, the samples from traditional dairy products such as yogurt, doogh, dried kashk, and lolek were collected, and the diversity of lactic acid bacteria (LAB) was determined as L. lactis subsp cremoris, Streptococcus thermophilus, L. lactis subsp lactis, Lactobacillus plantarum, Lactobacillus helveticus, Lactobacillus bulgaricus, Lactobacillus casei, and Lactobacillus fermentum. The mean values of fat, protein, and TVN for dried and liquid kashk samples were measured as (7.4 ± 0.7, 2.7 ± 0.1%), (51 ± 3.8, 8.7 ± 0.6 g/100 g) and (15.3 ± 3.9, 14.9 ± 4.1 mg/100 g), respectively. The microbial analysis revealed yeasts and molds were the most prevalent microorganisms in both types of kashks, while no Coliform, Escherichia coli, and Staphylococcus aureus bacteria were found in all samples. In conclusion, the selected species from traditional products which presented a specific property may provide a wide range of genetic variants to design modified species with desired characteristics.

Chilling injury, fruit color maturity stages, and antioxidant enzyme activities of lemon 'baladi CV' fruits under cold storage stress

Lemon 'Baladi' is often harvested at different color stages (HFCS) for logistic support to market and customers. So, the evaluation of lemon fruit was harvested at three color stages (Green, G; Yellow-green, YG; Yellow, Y-stage) to determine an effect on enzymatic antioxidant activities (AEAs) and chilling injury (CI). Lemon fruits were stored at low temperature (4 ± 1 °C and relative humidity 95 ± 2%) for 60-days. The outcomes of this study provide that the G-stage fruits presented more resistance to low storage temperature stress for the long term, therefore less CI-symptoms incidence compared to other maturities (YG and Y-stage). Throughout cold storage, fruits were estimated the physical and chemical analyses every 15-days intervals. The G-stage promoted the highest activation in antioxidant enzyme activities. Consequently, the scavengers of radicals such as DPPH and ABTs test presented more quenching radicals. So, less CI symptoms incidence during 60 days of cold storage. Also, less malondialdehyde and ion leakage percentage related to other fruit color stages. These were significant impacts on CI and fruit color hue angle during storage.The G-stage revealed to be a good stage of lemon to store at low temperature due to it is tolerant to chilled temperature for long term.

Thermal, morphological, and physicochemical characteristics of succinylated–crosslinked rice starches

AbstractBackground and objectiveStarches were isolated from two indigenous rice varieties of Pakistan, namely Basmati and Irri. Effect of succinylation followed by crosslinking was studied on thermal, physicochemical, and morphological characteristics of Basmati and Irri starches.FindingsThe percent succinylation and crosslinking were found to be (8.5, 5.9)% and (88.77, 47.49)%, respectively. SEM micrographs revealed surface erosion of starch granules after succinylation. However, modifications were not found to affect granular integrity of starches. The pasting temperature reduced but peak viscosity increased after succinylation. The reduction in peak viscosity of succinylated–crosslinked Irri and Basmati starches was 89% and 47%, respectively, when compared to their succinylated counterparts, which could be attributed to formation of diphosphate linkages after crosslinking. The DSC analysis suggested improvement in granular stability after dual modification. After 7 days of cold storage, native starch gels were found to have significantly higher hardness in comparison with single‐ and dual‐modified starches.ConclusionsSignificant physicochemical alterations occurred after aforementioned dual modification. Findings suggest the use of succinylated–crosslinked rice starches in frozen foods, weaning baby foods, and soft confectionary products.Significance and noveltySuccinylation followed by crosslinking is a unique modification, which has never been reported on Pakistani Basmati and Irri rice starches. These findings provided fundamentals for the commercial applications of succinylated–crosslinked rice starches. Moreover, the use of inexpensive broken rice grains for preparation of dual‐modified starches could make product development cost‐effective.

Effects of chitosan with vegetable oil on shelf life of brown trout (Salmo trutta fario) fillets fed on prebiotics

AbstractIn this research, effects of chitosan coating of brown trout (Salmo trutta fario) fillets containing inulin were determined. Chitosan enriched by vegetable oils (0% Chitosan‐control, 2% acetic acid +Chitosan, 2% sage oil+Chitosan, and 2% mint oil+Chitosan) on shelf life was investigated. In the experiment, fish fillets from the control and the experimental groups were subjected to chemical and microbiological analyses at 0, 3, 6, 9, and 12 days of cold storage at 4 ± 1°C.Coating with chitosan enriched with different vegetable oils caused statistically significant effects on microbiological (total aerobic mesophilic, psychrotrophic, lactic acid, Enterobacteriaceae, and Pseudomonas) and chemical parameters (total volatile base–nitrogen and pH) (p &lt; .05), but not on thiobarbituric acid reactive substance values (p &gt; .05).Considering all of the data determined from the present study, it was found that fish fillets coated with chitosan enriched with mint oil gave the best results with respect to shelf life.Practical ApplicationTo use chitosan as coating material in fish processing. To enrich chitosan with vegetable oils for longer shelf life of fillets of brown trout fed on prebiotic, inulin. To report use of mint oil with chitosan as coating substance for the best results in storage of aquatic products.

Sex hormone intake in female blood donors: impact on haemolysis during cold storage and regulation of erythrocyte calcium influx by progesterone.

Sex hormone intake in blood donors may affect the quality of red blood cell (RBC) products via modulation of RBC function and predisposition to haemolysis during cold storage. The aims of this study were to evaluate the association between female sex hormone intake and RBC storage outcomes, and to examine possible mechanisms by which sex hormones interact with RBCs. Sex hormone intake by race/ethnicity and menopausal status, and association analyses between hormone intake and donor scores of storage, osmotic or oxidative haemolysis, were evaluated in 6,636 female donors who participated in the National Heart, Lung and Blood Institute's RBC-Omics study. A calcium fluorophore, Fluo-3AM, was used to define RBC calcium influx in response to exogenous sex hormones or transient receptor potential cation (TRPC) channel drugs. Sex hormone intake was more prevalent in premenopausal women from all racial groups (18-31%) than in postmenopausal women (4-8%). Hormone intake was significantly (p<0.0001) associated with reduced storage haemolysis in all females, reduced osmotic haemolysis in postmenopausal donors (23.1±10.2% vs 26.8±12.0% in controls, p<0.001), and enhanced susceptibility to oxidative haemolysis in premenopausal women. In vitro, supraphysiological levels of progesterone (10 μmol/L), but not 17β-oestradiol or testosterone, inhibited calcium influx into RBC and was associated with lower spontaneous haemolysis after 30 days of cold storage (0.95±0.18% vs 1.85±0.35% in controls, p<0.0001) or in response to a TRPC6 activator. Sex hormone intake in female donors is associated with changes in RBC predisposition to haemolysis. Menstrual status and the type of hormone preparation may contribute to differences in haemolytic responses of female RBCs to osmotic and oxidative stress. Progesterone modulates calcium influx into RBC via a mechanism that may involve interactions with membrane TRPC6 channels.

Characteristics of probiotic yoghurts supplemented with Pu-erh tea infusion.

Recently, interest in the development of functional foods enriched with bioactive components has increased. Dairy products supplemented with tea extracts known for their health-promoting properties are good examples of such products. However, most of the scientific studies and applications focus on green tea. The present study was established to estimate the effect of Pu-erh tea supplementation on the viability of starter microorganisms and selected physico-chemical and sensory properties of probiotic ABT-yoghurt. ABT-yoghurts (Lactobacillus acidophilus La-5, Bifidobacterium animalis ssp. lactis BB-12, Streptococcus thermophilus) were produced from cow&rsquo;s milk with 0%, 5%, 10% or 15% (v/v) of Pu-erh tea infusion added before the fermentation stage. The products obtained were subjected to the following analyses one day after production (colour profile) and after 7, 14 and 21 days of cold storage: ferric reducing antioxidant power (FRAP) and anti-radical power (ARP) measured against DPPH radical, titratable acidity, pH, texture parameters (back extrusion test), viability of starter cultures and sensory quality (hedonic scale experiment). Pu-erh tea supplementation significantly enhanced the antioxidant potential of probiotic yoghurts as a 3&ndash;6.5-fold increase in FRAP and a 10&ndash;24-fold increase in ARP values were observed in comparison to plain ABT-yoghurt. Pu-erh tea slightly enhanced the viability of L. acidophilus and reduced the pH of probiotic yoghurts. Higher concentrations of Pu-erh tea caused decreased firmness and consistency while cohesiveness and index of viscosity remained unaffected upon supplementation. The addition of Pu-erh tea infusion modified the colour and sensory properties of the probiotic yoghurts but the sensory quality of the tea yoghurts was rated lower when compared to the plain one. Among all tea yoghurts, the one with 15% Pu-erh tea additive received the highest scores in sensory assessment. Pu-erh tea may be successfully applied as a functional additive to probiotic yoghurts, signifi- cantly enhancing the antioxidant properties of fermented milk and ensuring a high rate of starter bacteria viability during storage. However, the level of fortification must be carefully chosen as some doses negatively influence texture parameters and sensory quality.

Use of thyme essential oil as an antibacterial agent in raw milk intended for the production of farm cheese

This study aims to use thyme essential oil (TEO) as an antibacterial agent in raw milk intended for the production of farm cheese and to test its effect on bacteriological and sensory quality. Antibacterial activity of TEO was first tested in vitro on four strains of bacteria known for their pathogenicity such as Escherichia coli , Pseudomonas aeruginosa , Salmonella typhimurium and Staphylococcus aureus and then in vivo on the total mesophilic aerobic flora (TMAF) in raw milk used to produce farm cheese. All tested bacteria were very sensitive to TEO with a higher sensitivity for Escherichia coli , followed by Pseudomonas aeruginosa , then Staphylococcus aureus and finally Salmonella tiphymirium. In vivo study showed that TEO has an effective effect on TMAF of raw milk. Monitoring bacteriological quality of TEO based farm cheese during 6 days of cold storage, revealed the effectiveness of TEO on TMAF, yeasts and moulds. Despite the good bacteriological quality of TEO-based farm cheese, the strong aroma characterizing this essential oil was not well appreciated by some tasters, which had a negative impact on the final score attributed to this cheese. Thyme essential oil can be used as an alternative solution to produce healthy farm cheese without needing heat treatment, while ensuring high nutritional value food product.