Bunker‐stored silage covered with biodegradable coating. Part I. Laboratory assay

The effect of a hydrophobic biodegradable coating on the conservation of silage was evaluated in comparison with unsealed silage and silage covered with a polyethylene (plastic). Silage samples were subjected to biochemical analysis (pH, dry matter, water‐soluble sugars, ammoniacal nitrogen, lactic acid) and microbiological analysis (total aerobes, lactic acid bacteria, moulds and yeasts) during 135 days of storage. Silage covered with the biodegradable coating had a constant pH value of 4.79 and was preserved against spoilage until day 120, whereas the pH of unsealed silage increased during the first 6 days to a value of 8.22. After 2 months of storage, silage covered with the biodegradable coating had a lower dry matter content, higher water‐soluble sugar content and higher lactic acid concentration than unsealed silage. During storage the population of total aerobes was lower in silage covered with the biodegradable coating than in silage covered with plastic. Furthermore, silage covered with the biodegradable coating had a stable content of aerobic micro‐organisms. The biodegradable‐coated silage showed a growth of lactic acid bacteria similar to that of silage covered with plastic. Only silage covered with the biodegradable coating had a low initial content of moulds and yeasts. Air infiltration was present throughout the storage period in the plastic and biodegradable coating treatments and was linked with the degradation of silage in both cases. However, the biodegradable coating significantly (P ≤ 0.05) increased the period of silage conservation compared with that of uncoated silage. Copyright © 2004 Society of Chemical Industry     

Development of biodegradable coatings for covered horizontal bunker‐stored silage

The addition of different plasticizers, thickeners and hydrophobic compounds such as fatty acids in biodegradable coatings has been evaluated using pH values and dry matter content as criteria in silage during one month of storage at room temperature under laboratory conditions. A base coating solution was prepared with whey protein concentrate, calcium caseinate and carboxymethylcellulose. From the base coating solution, derivative coating solutions were developed to evaluate the effect of plasticizers by incorporating glycerol at different concentrations and different ratios of sorbitol and glycerol. Thickening agents were also evaluated by adding fine silage powder, coarse silage powder, hay powder, or cornstarch. Derivative coating solutions were studied to evaluate the effect of fat constituents. Canola oil, beef fat, shortening, bees wax or candellila wax were added to the base solution following various procedures. Results showed that the addition of glycerol (320 g kg^?1) in the coating formulation resulted in a pH value of 5.21 after 31 days of storage without visible spoilage under the coating. The presence of plasticizer compounds avoids the appearance of cracking in the coating during the early stage of conservation. The pH of silage coated with formulations containing coarse or fine silage powder was preserved below 5 until day 17 as compared to the other formulations where the pH was preserved below 5 only for 10 days. The incorporation of beef fat in the coating formulation resulted in the lowest pH as compared to all the other fat compounds evaluated, showing a value of 4.61 at the end of storage. The addition of glycerol, coarse silage and beef fat in the same coating formulation recovered by a hydrophobic layer of zein stabilized the pH to 4.47 for 28 days of storage with a final dry matter content at 344.3 g kg^?1 without visible spoilage under the coating during all of the storage at room temperature. Copyright © 2004 Society of Chemical Industry     

Edible coatings for enhancing microbial safety and extending shelf life of hard-boiled eggs

ABSTRACT:  Hard-boiled eggs were coated with chitosan–lysozyme (CL), whey protein isolate (WPI), or Bake sheen (BS), inoculated with Listeria monocytogenes or Salmonella enterica Ser. Enteritidis at 10⁴ CFU/g, and stored for 4 wk at 10 °C. Microbial populations were enumerated weekly. Two nonchallenge studies were also conducted with hard-boiled eggs: coated shell-on eggs packaged in plastic containers or peeled eggs coated and vacuum-packaged. Total plate counts (TPC), coliforms, yeasts, molds, weight loss, pH, and color of eggs were determined during the 10-wk storage at 10 °C. Uncoated eggs served as controls. All the coatings were not effective in inhibiting the growth of L. monocytogenes, but CL coating controlled the growth of S. Enteritidis. At the end of 4-wk storage, the numbers of S. enteritidis on CL-coated eggs were about 4-log₁₀ CFU/g less than that of the controls. Coatings reduced ( P < 0.05) the populations of coliforms and TPC, and completely inhibited mold growth during the 10-wk storage. Coatings also reduced ( P < 0.05) the weight loss of eggs, 4.1% to 4.8% on coated eggs compared with 7.5% in uncoated ones at the end of 10-wk storage. The pH of CL-coated eggs remained stable throughout the storage period, while the control eggs increased from 7.6 to 8.6. Color changes in CL- and WPI-coated eggshells were less ( P < 0.05) than those of BS-coated and the control. The CL coating effectively suppressed the numbers of TPC, coliforms, yeasts, and molds on peeled eggs during the 6-wk storage ( P < 0.05). The results suggest that CL coating on hard-boiled eggs can control the growth of S. Enteritidis and reduce undesirable changes in the interior quality of eggs.     

Effectiveness of chitosan‐based coating in improving shelf‐life of eggs

Despite eggs having a natural packaging—shell—they are perishable and can lose their quality during storage. Chitosan‐based coatings were applied to shell eggs to examine potential effects on egg quality properties (weight loss, Haugh unit, yolk index) during 4 weeks of storage. Mineral amounts in yolks were also evaluated after 4 weeks of storage. Three chitosan‐based coatings produced with organic acids (acetic‐(C‐AA), lactic‐(C‐LA), and propionic (C‐PA)) were evaluated on shelf‐life enhancements of fresh egg quality. All chitosan‐coated eggs showed greater interior quality than the non‐coated eggs. The coatings significantly maintained weight loss compared to the control specimen (4.96%). Lower weight loss (3.45% for C‐PA, 3.53% for C‐LA) was observed in the coated eggs. Eggshell chitosan coat containing lactic and propionic acids maintained higher Haugh unit and yolk index than eggs coated with acetic acid. Uncoated (UC) eggs changed from grade ‘A’ to ‘B’ after 1 week of storage. Chitosan‐based coating containing lactic and propionic acids maintained eggs in grade ‘A’ for 4 weeks. Haugh unit showed that C‐LA and C‐PA effectively maintained eggs at grade ‘A’ quality for at least 3 weeks more than control and 1 week more than C‐AA. Results also indicated that the chitosan coating maintained mineral amounts at nutritional values (especially calcium, iron and magnesium concentration) in yolks after 4 weeks storage. Copyright © 2006 Society of Chemical Industry     

Composite starch-based coatings applied to strawberries (Fragaria ananassa)

Starch-based coatings were used to the extend storage life of strawberries (Fragaria ananassa) stored at 0 degree C and 84.8% relative humidity. Effects of coating formulation (including starch type, plasticizer, lipid and antimicrobial agent) were analysed with respect to fruit quality. Plasticizer addition was necessary for film and coating integrity to avoid pores and cracks. Plasticizer presence reduced weight losses and maintained surface colour of fruits. Amylomaize coatings showed lower water vapour and gas permeabilities and decreased weight losses for longer periods than corn starch ones. Coatings with sorbitol showed lower permeabilities than glycerol ones. Coatings with antimicrobial agents decreased microbial counts, extending storage life of coated fruits by 10 to 14 days in comparison to the control. The addition of 2 g/l sunflower oil to the formulations decreased the water vapour permeability of starch-based films, maintained the surface colour of coated fruits and controlled effectively fruit weight losses during storage. Lipid addition minimized the effects of starch and plasticizer types. Composite starch-based coatings showed selective gas permeability (CO2 higher than O2) which helps to delay senescence of fruits.     

Impact of edible coatings and packaging on quality of white asparagus (Asparagus officinalis, L.) during cold storage

The effects of edible coatings and plastic packaging on quality aspects of refrigerated white asparagus spears were studied using two different experimental protocols. The first included four coating formulations based on carboxymethyl-cellulose and sucrose fatty acid esters, whey protein isolate alone and in combination with stearic acid, and pullulan and sucrose fatty acid esters, and an uncoated sample serving as a control. The second set consisted of four treatments; uncoated asparagus spears (control), coated with a carboxymethyl-cellulose formulation, packaged in plastic packaging and combination of coated and packaged asparagus spears. All products were stored at 4 °C and the quality parameters such as weight loss, texture, visual appearance, lignin and anthocyanins concentration, and colour were evaluated during their storage. Edible coatings exhibited a beneficial impact on the quality of asparagus by retarding moisture loss, reducing hardening in their basal part and slowing down the purple colour development. The plastic packaging had a remarkable influence in reducing weight loss and retarding hardening but its impact to the rest of the quality parameters was similar to that of the edible coatings. The combination of packaging and edible coating did not seem to offer any additional advantage on asparagus spears apart from the fact that the product had a brighter appearance at the middle part of the stem compared to the packaged spears alone.     

Composite starch‐based coatings applied to strawberries (Fragaria ananassa)

Starch‐based coatings were used to the extend storage life of strawberries (Fragaria ananassa) stored at 0°C and 84.8% relative humidity. Effects of coating formulation (including starch type, plasticizer, lipid and antimicrobial agent) were analysed with respect to fruit quality. Plasticizer addition was necessary for film and coating integrity to avoid pores and cracks. Plasticizer presence reduced weight losses and maintained surface colour of fruits. Amylomaize coatings showed lower water vapour and gas permeabilities and decreased weight losses for longer periods than corn starch ones. Coatings with sorbitol showed lower permeabilities than glycerol ones. Coatings with antimicrobial agents decreased microbial counts, extending storage life of coated fruits by 10 to 14 days in comparison to the control. The addition of 2 g/l sunflower oil to the formulations decreased the water vapour permeability of starch‐based films, maintained the surface colour of coated fruits and controlled effectively fruit weight losses during storage. Lipid addition minimized the effects of starch and plasticizer types. Composite starch‐based coatings showed selective gas permeability (CO₂ higher than O₂) which helps to delay senescence of fruits.     

Effect of native and acetylated‐crosslinked waxy corn starch‐beeswax coatings on quality attributes of raspberries during storage

Edible coatings (ECs) are a thin layer of a mixture of edible materials, applied in the liquid state and dried over the surface of a food product to maintain its quality during storage. This work was aimed to study the effect of ECs made from wx corn starch (WCS) or acetylated cross‐linked starch (ACLS) added with beeswax on fresh raspberry quality attributes during short‐term cold storage. Freshly harvested fruits were coated, dried, packed in plastic trays and stored up to 8 days at 4°C. During storage quality parameters such as firmness, respiration rate, anthocyanins content, total phenols, color changes, and weight loss were evaluated. A clear effect on control of respiration rate was observed in coated raspberries. Respiration rate of uncoated fruit was 4.5 ± 0.28 mmol/kg/h and decreased to 4.2 ± 0.27 for ACLS and to 4.1 ± 0.08 mmol/kg/h for WCS‐coated raspberries, after 56 h of storage at 15°C. Ethylene production followed a similar trend under these conditions decreasing from 0.043 ± 0.005 to 0.034 ± 0.004 mmol/kg/h for uncoated and ACLS coated fruits, respectively, indicating an effect on ripening control. Additionally, ACLS and WCS coatings permitted the preservation of color without affecting anthocyanins content. However, the presence of anaerobic metabolites and reduction of terpenes production in cold stored coated raspberries indicated hypoxic conditions, which can adversely affect shelf‐life quality attributes of raspberries such as firmness and weight loss.     

Efficacy of cellulose-based coating on enhancing the shelf life of fresh eggs

Methylcellulose (2.00% w/v) and hydroxypropyl methylcellulose (1.00% w/v) -based coating was formulated to study the effects of polyethylene glycol-400 (PEG-400) and a stearic and palmitic acid blend (SPB) on water vapour permeability (WVP) and tensile properties. The efficacy of cellulose-based coating on fresh egg quality during 28-day storage at ambient temperature was investigated in terms of weight loss, pH, and albumen quality. The selected formulation obtained by a response surface analysis was 1.00% w/v PEG-400 and 4.00% w/v SPB. An edible cellulose-based solution was prepared for eggshell coating. A batch of fresh, grade AA 1-day eggs was coated with cellulose-based coating solution. The other batch consisted of uncoated eggs, which served as the control. Lower weight loss (4.28%) was observed in the cellulose-based coated eggs, compared to 8.83% for the uncoated eggs. The pH in albumen of coated and uncoated eggs increased from 8.71 and 8.72 to 9.44 and 9.76, respectively, after 4 weeks of storage. For albumen quality, Haugh units indicated that after 7 days, cellulose-based coated eggs changed from grade AA to grade A, and remained in grade A throughout the storage period; whereas after 5 days, uncoated eggs started to change from grade AA to grade A, and continually degraded to grade B during the 4 weeks of storage. This study highlights the promising use of cellulose-based coating to enhance the shelf life of fresh eggs.     

Quality and Shelf Life of Cold and Frozen Rainbow Trout (Oncorhynchus mykiss) Fillets: Effects of Fish Protein-Based Biodegradable Coatings

The Klunzinger’s ponyfish (Equulites klunzingeri) protein powder extracted with acid or alkali aided process as a biodegradable coating material for rainbow trout (Oncorhynchus mykiss) fillets during cold (+2°C) and frozen storage (–18°C) were investigated. The coating with alkaline treated protein (AlPC) and acid treated protein (AcPC) extended the shelf life of fillets from 11 to 14 days in cold storage and improved the quality parameters in three months frozen storage period. According to total viable count and total psychrophile count results, bacteria grew more quickly in uncoated fillets than coated fillets. The protein-based coating did prevent spoilage of the rainbow trout fillets as reflected by a decrease in pH, total volatile base-nitrogen and free fatty acids during cold and frozen storage period. Therefore, this study demonstrated that fish protein-based coating had a positive effect on maintaining the rainbow trout fillets quality, and edible coatings from discard fish can offer a promising alternative for preserving fish fillets.     

Effect of solid content and composition of hydroxypropyl methylcellulose–lipid edible coatings on physicochemical,sensory and nutritional quality of ‘Valencia’ oranges

‘Valencia’ oranges were coated with edible coatings based on hydroxypropyl methylcellulose (HPMC), beeswax (BW) and shellac. Coatings were prepared at two BW/shellac ratios (1:3 and 3:1) and two solid content (SC) (4% and 8%). A commercial wax at a 10% SC, as a control of coated fruits, and an uncoated control were also tested. Oranges were stored up to 16 weeks at 5 °C, followed by 1 week at 20 °C. Although sensory quality was not negatively affected by coating application, care should be taken to the SC and shellac content of the formulations, since an increase in these parameters translated in a significant increase in the level of ethanol. Results indicate that HPMC–BW–shellac coating with 4% SC and a BW/shellac ratio 1:3 would provide the best compromise to extend shelf life of ‘Valencia’ oranges by reducing weight loss, providing gloss and maintaining the nutritional quality of the fruits.     

A novel emulsion coating and its effects on internal quality and shelf life of eggs during room temperature storage

Effects of mineral oil (MO), chitosan solution (CH) and their emulsions (MO:CH = 75:25, 50:50, and 25:75 ratios) as coating materials in preserving internal quality of eggs were evaluated during a 5‐weeks storage at 25 °C. Consumers (n = 109) evaluated surface properties and purchase intent of freshly coated eggs. As storage time increased, Haugh unit and yolk index values decreased whereas weight loss increased. Noncoated eggs rapidly changed from AA to B and C grades after 1 and 3 weeks, respectively. However, all emulsion‐coated eggs maintained their A‐grade quality for 4 weeks. Compared with noncoated eggs, all emulsion coatings reduced weight loss of eggs by at least seven times (0.88–1.03% vs. 7.14%). Only MO:CH = 25:75 emulsion‐coated eggs were not sensorially glossier than noncoated eggs. All emulsion‐coated eggs had >80% positive purchase intent and were negative for Salmonella. This study demonstrated that MO:CH emulsion coatings preserved internal quality and prolonged shelf life of eggs.     

Chitosan-soybean oil emulsion coating affects physico-functional and sensory quality of eggs during storage

Effects of soybean oil (SO) and chitosan-soybean oil (CH:SO = 40:60) emulsion as coating materials for preserving internal quality of eggs were evaluated during 7 and 15 weeks storage at 25 °C and 4 °C, respectively. Consumers (n = 150) assessed surface properties and purchase intent of freshly coated eggs. Noncoated eggs deteriorated from AA to B grade after 1 week while coated eggs retained A grade up to 5 weeks at 25 °C. Amongst coatings, CH:SO emulsion maintained a lower albumen pH while SO was better at reducing weight loss. Effect of refrigeration on albumen pH was minimal. Weight loss of coated eggs was <3% after 7 weeks at 25 °C. Emulsion capacity and emulsion viscosity were minimally affected by coating and refrigeration, and their trends were more correlated to the yolk index at 25 °C than at 4 °C. Only SO-coated eggs were not sensorially smoother than noncoated eggs; however, CH:SO emulsion-coated eggs had the least shell colour changes (ΔE^∗, values at day 0 as a reference) during storage at 25 °C. All coated eggs had 85% positive purchase intent. SO and CH:SO emulsion coatings significantly extended egg shelf-life compared to that of noncoated eggs at room and refrigerated storage.     

Effects of silage pH on voluntary intake of corn silage

We evaluated effects of silage pH on corn silage intake. Sixteen Holstein heifers (292 kg) were fed control corn silage during a 2-wk preliminary period. This was followed by an 8-wk experimental period in which animals were fed silage neutralized with 0, 2, 4, or 6% sodium bicarbonate (dry matter) added prior to feeding with corresponding pH's 3.72, 4.46, 5.62, and 8.05. Organic matter intake was increased 1.0 and 1.2 kg/day by addition of 2 and 4% sodium bicarbonate versus controls whereas 6% sodium bicarbonate reduced intake .7 kg/day. An equation developed to predict organic matter intake from silage pH was: Y = 3.20 + 3.92 (pH) -.35 (pH)2 with coefficient of determination .66. This equation predicted maximum organic matter intake at pH 5.6. It appears that silage pH is a factor that affects voluntary consumption of corn silage and that pH 5 to 6 is optimum, whereas silage pH above and below may reduce intake.     

EFFECT OF SODIUM ALGINATE COATING WITH PRESERVATIVES ON THE QUALITY OF MEAT PATTIES DURING REFRIGERATED (4 ± 1C) STORAGE

Edible coatings are the substances that are used to preserve and enhance food quality. An attempt was made to improve the quality of buffalo meat patties (BMPs) by method of alginate coating involving dipping BMPs during the end of the broiling process in alginate solution with preservatives for 30 s, followed by dipping in calcium chloride solution for 30 s, followed by draining for 30 s. The coated BMPs were kept at refrigeration (4  ±  1C) temperature in a polyethylene bag. They were analyzed for quality changes at regular intervals. Alginate coating significantly ( P ≤  0.05) decreased the overall shear force values, thiobarbituric acid and tyrosine value, total plate count, psychrophilic count, and yeast and mold count. The enterobacteriaceae count could not be detected. The coating at 2% level significantly ( P ≤  0.05) improved the overall appearance and color, juiciness, flavor, texture and overall palatability of the product. During storage, the overall values for shear force, TBA, pH, tyrosine and count for total plate, psychrophilic, yeast and mold, and staphylococcal, increased linearly. The overall sensory scores of the products decreased linearly with storage time.

PRACTICAL APPLICATIONS

Edible coating of meat products provides better protection against oxidative and microbiological deterioration. It can also significantly enhance the sensory qualities of meat products. The freshness of meat products is comparatively prolonged.     

不同微生物青贮剂对全株玉米青贮饲料的影响

选用两种不同的青贮发酵剂对全株玉米进行发酵,观察发酵8 d、10 d、20 d、40 d两种青贮发酵剂对全株玉米微生物消长及营养品质的影响。结果表明,经两种青贮发酵剂处理后,全株玉米青贮饲料均有酒香味;发酵前期（8 d、10 d）乳酸菌生长迅速,酵母菌生长相对缓慢。两种发酵剂对全株玉米青贮饲料的pH值、水分、粗蛋白、粗脂肪、粗灰分和粗纤维含量的影响差异不大,但对总酸、中性洗涤纤维和酸性洗涤纤维含量影响差异较大,青贮发酵剂B适合短期发酵使用,而青贮发酵剂A适合长期发酵保藏使用。两种青贮发酵剂处理的全株玉米青贮饲料中的限制因子（挥发性盐基氮、霉菌、黄曲霉毒素B1、玉米赤霉烯酮、呕吐毒素）均符合相关标准要求。     

The effect of edible eggshell coatings on egg quality and consumer perception

Effects of the various coatings (whey protein isolate, chitosan and shellac) on fresh eggs quality were evaluated based on the interior quality and sensory evaluation during 4 weeks of storage. During storage, all egg weights and albumen heights decreased and albumen pH increased. The lowest weight loss (0.75%) was observed in shellac‐coated eggs. Eggs coated with chitosan and whey protein also had significantly lower weight loss than uncoated (UC) eggs (p < 0.05). The albumen pH of the UC eggs was significantly higher than that of coated eggs and increased during storage time. The Haugh unit and yolk‐index values of all coated eggs were significantly higher than those of UC. Among the coated eggs, the shellac eggs had the highest value of Haugh unit and yolk index. Chitosan and shellac effectively maintained grade ‘A’ eggs for at least 2 weeks more than control and 1 week more than whey protein isolate. On the basis of sensory evaluation, shellac has highest glossiness, but lowest general acceptability. Eggs coated with whey protein had significantly higher general acceptability. Yolk lightness (L*)(a*) and (b*) of coated eggs were not different from UC after 4 weeks. The values of color differences were similar to controls. The study demonstrated that various coatings improved the shelf life of eggs. Copyright © 2005 Society of Chemical Industry     

Effects of mineral oil coating on internal quality of chicken eggs under refrigerated storage

The selected internal qualities (weight loss, Haugh unit, yolk index, and albumen pH) of noncoated and mineral oil‐coated chicken eggs during 15 weeks of storage at 4 °C and/or during 5 weeks of storage at 25 °C were evaluated. Results indicated that, without refrigeration, the noncoated and mineral oil‐coated eggs rapidly changed from AA to C and B grades as measured by Haugh unit, respectively, after 5 weeks of storage. However, the AA quality of the noncoated eggs could be maintained under refrigerated storage (4 °C) for at least 5 weeks. The mineral oil coating and refrigerated storage (4 °C) synergistically minimised weight loss and preserved the albumen and yolk qualities of chicken eggs during a long‐term storage. At 4 °C, the mineral oil‐coated eggs preserved the initial AA grade for at least 15 weeks with l.19% weight loss.     

Low permeability to oxygen of a new barrier film prevents butyric acid bacteria spore formation in farm corn silage

The outgrowth of Clostridium spore-forming bacteria causes late blowing in cheeses. Recently, the role of air diffusion during storage and feed-out and the role of aerobic deterioration has been shown to indirectly favor butyric acid bacteria (BAB) growth and to determine the presence of high concentrations of BAB spores in farm tank milk. A new oxygen barrier (OB) film was tested and compared with conventional polyethylene (ST). The objective was to verify whether the OB film could prevent BAB spore formation in whole-crop corn silage during storage on 2 commercial farms with different potential silage spoilage risks. Two bunkers (farms 1 and 2) were divided into 2 parts along the length so that half the feed-out face would be covered with ST film and the other half with OB film. Plastic net bags with freshly chopped corn were buried in the upper layer and in the central part (CORE) of the bunkers. The silos were opened in summer and fed out at different removal rates (19 vs. 33 cm/d). Herbage at ensiling, silage at unloading, and silage after air exposure (6 and 15 d) were analyzed for pH, nitrate, BAB spores, yeasts, and molds. The BAB spores in herbages at ensiling were 2.84 log₁₀ most probable number (MPN)/g, with no differences between treatments or farms. Nitrate was below the detection limit on farm 1 and exceeded 2,300 mg/kg of fresh matter on farm 2. At unloading, the BAB spores in the ST silage on farm 1 were greater than 5 log₁₀ MPN/g, whereas in the CORE and the OB silages, they were approximately 2 log₁₀ MPN/g. The ST silage had the greatest pH (5.89), the greatest mold count (5.07 log₁₀ cfu/g), and the greatest difference between silage temperature and ambient temperature (dT_{section-ambient}). On farm 2, the ST silage had the greatest concentration of BAB spores (2.19 log₁₀ MPN/g), the greatest pH (4.05), and the least nitrate concentration compared with the CORE and the OB silages. Pooled data on BAB spores collected from aerobically deteriorated samples showed a positive relationship with pH, mold count, and dT_{section-ambient} and a negative relationship with nitrate concentration. A high concentration of BAB spores (>5 log MPN/g) was associated with visible spoilage, high pH values (>5.00), high mold counts (>5 log cfu/g), high dT_{section-ambient}, and nitrate below 1,000 mg/kg of fresh matter. We concluded that the use of a film with reduced oxygen permeability prevented the outgrowth of BAB spores during conservation and feed-out, and it could improve the microbiological quality of corn silage by eliminating the fractions of silage with high BAB spore concentrations.     

含肉桂精油的壳聚糖涂层对冷藏草鱼片的保鲜作用

通过在草鱼片上添加含肉桂精油(CIN)的壳聚糖(chitosan,Ch)涂层,研究含肉桂精油的壳聚糖涂层对草鱼片(4±1)℃ 冷藏16 d期间品质的影响.涂层分别采用质量浓度20 g/L Ch和Ch+CIN[质量浓度20 g/L Ch+1.5％(体积分数)CIN]配方溶液,对未添加涂层和添加不同配方涂层鱼片样品的微生物...