Effects of salt mixtures on Spanish green table olive fermentation performance

This work investigates the effect of sodium, potassium, and calcium chloride salts on the performance of Spanish green table olive fermentation using a simple centroid mixture design. The presence of calcium chloride hindered the diffusion of all sugars and delayed the period required to reach their respective maximum concentrations in brines. Such effects can prevent tumultuous processes and gas pocket spoilage. Acetic acid was present at low concentrations in all treatments but was not generated during fermentation. The production rate of lactic acid was either decreased or delayed by the presence of calcium chloride but adequate final conditions were always reached. The chemometric analysis classified treatments into groups according to the presence of calcium chloride and disclosed a stimulating effect of potassium on lactic acid production. Therefore, these techniques can be a useful tool to investigate olive fermentation performance. According to the results, acceptable Spanish green table olives can be produced using salt mixtures, with the subsequent reduced sodium content in the final products. The results obtained in this study could also be of interest for other fermented vegetables.     

Absorption of sorbic and benzoic acids in the flesh of table olives

The distribution of sorbic and benzoic acids in the different phases of table olives was studied. To a large extent, these preservatives accumulated in the oil phase of fruits stored in acid conditions, as well as in juice and other tissue components. Thus, around 20–30% of the benzoic acid in olives was found in the juice phase, 30–50% in the oil phase and 30–40% in the rest of the olive flesh. Experiments carried out with black ripe olives revealed that an increase in pH of the medium gave rise to a decrease in the absorption phenomenon in whole olives and in the oil phase. As a consequence of this effect, benzoic acid could be leached from stored black ripe olives during the darkening process, although the calcium content of fruits greatly influenced the diffusion phenomenon. The results obtained in this study are important for future legal limitations of these preservatives in table olives and inhibition capacity of them in commercial table olives.     

Effect of prepartal hormone administration on feed intake and mineral metabolism of cows.

Subcutaneous administration of progesterone (.25 mg/kg body weight per day) to mature cows from 14 days before projected parturition until parturition increased feed intake over control cows. Incidence of milk fever and plasma calcium, phosphorus, magnesium, and hydroxyproline were not significantly different between treated and control cows. Subcutaneous administration of estradiol-17beta (.05 mg/kg body weight per day) or oral administration of melengestrol acetate (1 mg/day) from 7 days before projected parturition date until parturition decreased feed intake over control cows. Milk fever incidence and absorption of calcium, phosphorus, and magnesium were not significantly different between treatment groups. Plasma calcium was not significantly different between treatment groups during either the prepartum or postpartal periods but tended to be higher postpartum in cows treated with estrogen.     

Short communication: The effect of calcium supplementation at calving on neutrophil function

Low total blood calcium concentration after calving has been demonstrated to be a risk factor for reduced neutrophil function. The objective of this study was to evaluate whether administration of an injectable calcium supplement product soon after calving increased neutrophil oxidative burst or phagocytosis capacity. Cows (n = 27) from 4 farms were blocked by parity and randomly assigned to receive either calcium gluconate (35% wt/vol) in combination with calcium glucoheptonate (10% wt/vol; Theracalcium, Vétoquinol Canada Inc., Lavaltrie, Quebec, Canada) or a placebo within 12 h after calving and again 24 h later. Each dose of 120 mL was injected subcutaneously over 2 sites. Total serum calcium concentration, neutrophil oxidative burst, and neutrophil phagocytosis capacity were measured from coccygeal blood samples before (time 0) and 72 h after first treatment. There was no difference between treatment groups in lactation number, total calcium concentration, oxidative burst, or phagocytosis at time of enrollment. There was no effect of treatment on oxidative burst or phagocytosis by neutrophils. This preliminary study does not support an effect of supplemental calcium to improve neutrophil oxidative burst or phagocytosis capacity of low-parity parturient cows.     

微波消解-原子吸收法测定食品中的钙含量

目的建立微波消解-原子吸收法测定食品中钙含量的方法。方法采用微波消解法对样品进行前处理,在检测样品中加入氯化镧(8 g/L)屏蔽剂,用火焰原子吸收法进行检测。比较经消解后样品中不同的硝酸浓度对钙含量测定结果的影响,探究微波消解法测定食品中钙含量时结果偏低的原因。结果经微波消解后,样品中的硝酸含量大于0.5%时,会导致钙含量的检测结果偏低。经湿法消解处理的样品,其加标回收率在97.2%~106.0%之间,经微波消解法处理的样品,其加标回收率在96.8%~104.0%之间。将采用上述两种消解方法处理的样品的钙含量检测结果进行比较,测定值间的相对误差为1.64%~3.08%,在可接受范围内。结论微波消解-原子吸收法可以用于食品中钙含量的检测。     

Effects of high pressure and heat treatment on the mineral balance of goats' milk

Changes in the distribution of minerals in skim goats' milk by high pressure (400 MPa) and/or heat (85 degrees C for 30 min) treatment have been studied. Heat treatment caused reduced solubility of the calcium, magnesium and phosphorus, and this increased with the severity of heating. In contrast, high pressure released different levels of micellar elements into the soluble phase without causing appreciable changes in pH or ionic calcium concentration. The levels of soluble salts returned to their original values when the heated samples were subjected to high pressure. However, heating pressurized milk resulted in concentrations of soluble minerals that were lower than in control milks, and close to values found in heated milks. The salt balance in goats' milk was less affected by high pressure treatment at 75 degrees C than was that of cows' milk. These results are discussed in relation to the effects of high pressure and heat treatment on mineral equilibrium and micellar structure.     

Effects of Calcium and Pressure Treatment on Thermal Gelation of Soybean Protein

ABSTRACT:  The effect of calcium and high-pressure (HP) treatment on the heat gelation of soybean proteins was investigated. In the presence of calcium (2 to 25 mM), the gelation of dispersions of soybean protein isolate (SPI), a β-conglycinin-enriched fraction (7SEF), and a glycinin-enriched fraction (11SEF) started with protein having a lower degree of denaturation. The gels from these dispersions had greater stiffness than the samples without added calcium. HP treatment had different effects on heat-induced gelation depending on the presence of calcium and on the nature of the proteins. In the absence of calcium, gels with low stiffness were formed after HP treatment, compared with untreated samples, and regardless of the sample type (SPI, 7SEF, 11SEF). In the presence of calcium, gel stiffness was increased after HP treatment of dispersions containing β-conglycinin (SPI and 7SEF), while the opposite effect was observed for 11SEF. In the presence of calcium, HP treatment promoted a greater contribution of hydrophobic interactions in SPI and 7SEF. In the dispersions containing β-conglycinin, these conditions also promoted the appearance of a heterogeneous distribution of molecular sizes, from enormous aggregates to dissociated species. Our results suggest that, in the presence of calcium, HP treatment has an opposite effect on the ability of glycinin and β-conglycinin to participate in the formation of a 3-dimensional network upon heating.     

乳酸菌生长最佳培养基的筛选

文中通过检测乳酸菌在不同固体和半固体培养基中的菌落数,菌落大小及溶钙圈大小,以筛选出乳酸菌生长的最佳培养基,实验表明,在添加胡萝卜汁的乳酸菌分离固体培养基上,乳酸菌生长最好,活菌数含量最高,菌落和溶钙圈最大,同种培养基,半固体培养较固体培养更适于乳酸菌生长,前者出菌快,活菌数多。     

Calcium phosphate deposition from simulated milk ultrafiltrate on different stainless steel-based surfaces

In order to reduce the fouling caused by milk during heat treatment, it is important to know more about the precipitation process of calcium phosphate, the main mineral component of milk deposits. This work was mainly focused on the relationship between calcium phosphate fouling behaviour and the surface properties of the materials used as metallic substrata. The foulant solution used in this work was an aqueous solution that simulates the mineral composition of milk and the deposition of calcium phosphate was studied on several stainless steel-based surfaces with different surface energy properties, obtained by ion implantation (SiF₃+ and MoS₂), coating by plasma chemical vapor deposition (SiO_x) or autocatalytic coating (Ni-P-PTFE). The experiments were performed in a batch system, using a rotating disk apparatus. The calcium phosphate deposits formed were characterized according to the rate of formation, thickness and resistance to removal under increasing shear stresses. Based on the data presented in this work, it could be concluded that fouling caused by calcium phosphate is affected by the surface energy properties of the metal substrata since different surfaces develop different deposit structures which have, consequently, different resistance to removal.     

A study of the soluble complexes formed during calcium binding by soybean protein hydrolysates

ABSTRACT:  The soluble complexes formed between hydrolyzed soybean protein and calcium at pH 7.4 were investigated using dialysis, gel chromatography, and Fourier transform infrared spectrometry (FTIR). The results demonstrate that the amount of calcium bound was significantly different for soybean protein hydrolysates obtained using the proteases neutrase, flavourzyme, protease M, and pepsin. Maximum levels of calcium binding (66.9 mg/g) occurred with hydrolysates produced using protease M. Peptide fragments exhibiting high calcium binding capacity had molecular weights of either 14.4 kDa or 8 to 9 kDa, and the calcium binding capacity was linearly correlated with carboxyl group content ( R ²= 0.8204). FTIR experiments revealed that upon binding calcium, the amide I band underwent a shift to lower wave numbers. A wide, intense Ca–O absorption band also appeared between 400 and 100 cm⁻¹ in the far-infrared spectrum. The width and intensity of this band increased after treatment of samples with glutaminase. The amount of bound calcium was related to both the molecular weight of the peptides and to the carboxyl group content, and the most likely sites for calcium binding are the carboxyl groups of Asp and Glu.     

Changes in calcium level and mechanical properties of apple tissue due to impregnation with calcium salts

The purpose of this paper was to analyze the ability of apple matrix for calcium incorporation by two different impregnation techniques (in vacuum or at atmospheric pressure) and to determine the effect of these treatments on material compression behavior. According to the operative pressure, calcium incorporated in 200 g of fruit would satisfy about 23–62% of the Adequate Intake for adults. The greatest calcium content (3100 ppm) was reached after 22 h atmospheric impregnation process, while the calcium amount incorporated during vacuum treatment was similar to the one obtained after ≅10 h atmospheric process. Calcium impregnated tissues exhibited different response to compression as compared with raw fruit, showing a decrease in the values of failure force and modulus of deformability.     

Calcium Addition,pH and High Hydrostatic Pressure Effects on Soybean Protein Isolates—Part 2: Emulsifying Properties

Soybean protein isolates (SPI) represent an important source of proteins that are used to prepare oil-in-water (o/w) emulsions. The influence of an innovative treatment (high hydrostatic pressure, HHP) combined with calcium addition at different pH levels and protein concentrations on the formation and stability of o/w SPI emulsions was evaluated in this work. When applied separately, calcium addition or HHP treatment produced different effect at pHs 5.9 and 7.0. Calcium addition led to stable emulsions with decreased flocculation index (FI) at pH 5.9 and low protein concentration (5 g L^?1), whereas at pH 7.0, this effect was observed at high protein concentration (10 g L^?1). In these conditions, calcium would favor the arrival of big aggregates to interface, which would be modified and adsorbed during homogenization. Treatment with HHP decreased FI and stabilized emulsions during storage at pH 7.0 (but not at pH 5.9) when prepared from 10 g L^?1 protein dispersions. In these conditions, protein unfolding due to HHP-induced denaturation, and high ζ-potential would be responsible for emulsion improvement. Combination of calcium addition and HHP treatment impaired both formation and stabilization abilities of SPI at both pHs. Bridging flocculation was enhanced in these samples while interfacial protein concentration and percentage of adsorbed protein were increased. Thus, soybean proteins that were subjected to combined calcium addition and HHP treatment exhibited a great ability to associate each other, what can be useful to improve other functional properties such as gelation.     

Occurrence of Listeria monocytogenes in green table olives

Microbiological safety of green table olives from different cultivars, prepared by both the Spanish-style and biological methods and fermented with starter cultures of lactic acid bacteria (Lactobacillus plantarum, Lactobacillus casei, and Lactobacillus pentosus), was investigated. The fermentation process was monitored by measuring pH values, titratable acidities, and growth of lactic acid bacteria over time. During fermentation, lactic acid bacteria and yeasts were major microbial populations. Microbiological safety was evaluated by analysis for Listeria monocytogenes with the use of an enrichment method during storage (from 55 days to 18 months). Results demonstrated that L. monocytogenes can survive and grow in green table olives. L. monocytogenes was found in one of the commercial (thermally treated) samples analyzed and in all samples older than 2 months, irrespective of olive cultivar, lactic acid bacteria starter used, pH and titratable acidity of brine samples, or treatment applied.     

Effect of calcium on the physical properties of stirred probiotic yogurt

The effect of calcium on the viscosity, firmness, and smoothness, as determined by extent of nodulation, of stirred probiotic yogurt produced by bacterial fermentation was investigated. Standardized milk for yogurt manufacture was prepared, and calcium was added or removed from the system. Calcium was added as Ca²⁺ in the form of CaCl₂ (up to 13.6 mM) or nonionic calcium as Gadocal-K (calcium potassium citrate; up to 49.8 mM). Calcium was removed by chelating with sodium citrate (up to 16 mM) or by cation exchange with Amberlite IR-120 plus (sodium form) resin (up to 10 g/L). Calcium chloride and sodium citrate were added either before or after heat treatment of milk, and nonionic calcium was added before heat treatment. Calcium removal by ion exchange was performed before heat treatment. Neither Ca²⁺ addition nor removal by chelation with citrate resulted in stirred yogurt with viscosity, firmness, and smoothness superior to those of the control yogurt, whereas addition of 49.8 mM nonionic calcium and removal of calcium (5.6 mM or ∼10% of total calcium) by cation exchange improved the firmness and viscosity without affecting yogurt smoothness. The study identified Gadocal-K as a possible source of calcium fortification of stirred yogurt without loss of texture.     

不同盐对木薯淀粉结构的影响

为研究不同盐对木薯淀粉结构的影响,利用LiCl、LiNO3、CaCl2和Ca(NO3)2的醇溶液处理木薯淀粉,并通过扫描电子显微镜(scanning electron microscopy,SEM)、激光共聚焦显微镜(confocal laser scanning microscopy,CLSM)、X-射线衍射仪(X-ray diffraction,XRD)、傅里叶变换红外光谱仪(fourier transform infrared spectroscopy,FTIR)以及同步热分析仪对处理淀粉进行表征,并对直链淀粉含量(amylose content,AM)进行检测。结果表明:虽然盐/醇处理后的木薯淀粉仍维持其颗粒的完整性,但其内部结构受到严重破坏。处理淀粉的晶型未受到破坏,但其相对结晶度按LiNO3、LiCl、Ca(NO3)2到CaCl2的顺序依次降低。盐/醇处理使淀粉在3424和1645cm^-1处的FTIR峰向低波数方向移动。此外,与原淀粉相比,除LiNO3处理的淀粉的直链淀粉含量增高外,其余的样品均降低。而处理淀粉的最大分解温度均低于原木薯淀粉,其降低顺序与其相对结晶度降低顺序相符。综上可知,在乙醇溶液中,不同盐对木薯淀粉结构的影响存在明显的差异性,而通过两两对比可知,Ca^2+对木薯淀粉的作用强于锂离子,而Cl^-则强于NO3^-。     

山梨酸盐与钙胁迫对甜樱桃灰霉病抗性的诱导作用

以‘秦樱1号’樱桃为试材,研究不同质量浓度山梨酸钾（1、3、5、7 g/L）、CaCl2（5、10、15、 20 g/L）处理对离体灰霉菌的抑制效果,通过菌丝生长抑制率、扫描电子显微镜观察芽管生长及孢子萌发抑制率 筛选出最佳处理质量浓度。结果表明：与对照组相比,山梨酸钾、CaCl2处理均能不同程度地抑制灰霉菌菌丝的生 长,抑制灰霉菌芽管的伸长,降低孢子的萌发率,抑制效果随质量浓度的升高逐渐加强,20 g/L CaCl2、5 g/L山梨 酸钾处理抑制效果最好。以无菌水为对照,用采前喷20 g/L CaCl2、采后5 g/L山梨酸钾处理及二者复合处理接种灰 霉菌的甜樱桃,在（23±1）℃下存放5 d,通过测定发病率、病斑直径及相关酶活力探究不同处理对甜樱桃灰霉病 的抑制效果。在活体接种实验中,与对照组相比,20 g/L CaCl2、5 g/L山梨酸钾单独及复合处理均能有效抑制接种 到甜樱桃果实上灰霉菌的生长,减缓病斑的扩展,CaCl2与山梨酸钾处理能显著抑制樱桃果实中MDA含量上升,诱 导果实合成与积累抗性相关酶（多酚氧化酶、过氧化物酶、几丁质酶、β-1,3-葡聚糖酶）在接种1 d后或接种3 d后的 活力提高,以5 g/L山梨酸钾与20 g/L CaCl2复合处理抑制效果最好,该研究为降低由灰霉菌侵染引起的病害及采后 甜樱桃果实防腐保鲜提供了参考。     

TENDERNESS IMPROVEMENT OF BOVINE BICEPS FEMORIS MUSCLE BY CALCIUM CHLORIDE INJECTION

Injection of 0.25 M calcium chloride solution in less tender muscles, such as Biceps femoris, from relatively old animals produced tenderness increase in a shorter aging time (2 days). Protein degradation obtained after submitting muscle samples to the combination of calcium treatment plus two days of aging, was comparable to the proteolysis observed after 7 days of aging (Light Microscopy, Transmission Electron Microscopy, Polyacrylamide Gel Electrophoresis). Consumers were not only able to detect the resulting tenderness increment but also preferred calcium treated samples. The practice of calcium treatment on this widely used muscle -which is less tender, or with tenderness inconsistencies- has a benefit for both the industry and consumers.     

氯化钙对超高压处理的鲜切马铃薯硬度改善效果的研究

超高压（Ultra-high pressure,HPP）会造成鲜切马铃薯硬度的下降,为探究氯化钙对HPP处理的鲜切马铃薯硬度的改善效果,以鲜切马铃薯为原料,在不同氯化钙处理浓度、时间和浸泡方式下对HPP处理的鲜切马铃薯硬度的变化进行研究。结果表明：氯化钙真空浸渍硬度改善效果优于普通浸泡;在此基础上,采用响应面试验对氯化钙的改善效果进行优化分析得出不同浓度氯化钙及不同真空浸渍时间与不同超高压压力、压力作用时间作用于鲜切马铃薯是交互影响的,且氯化钙溶液浓度对鲜切马铃薯的质地影响最大。在HPP压力为300 MPa,作用时间10 min结合1.0%CaCl2,真空浸渍10 min 的处理条件下,鲜切马铃薯硬度值最大,为3284.83g,与未处理的鲜切马铃薯硬度相当,钙离子含量最高,为3157.82 ug/g,显著高于未处理组钙离子含量。     

钙离子选择性电极法测定饮料中游离钙含量的影响因素及其应用

目的:钙离子选择性电极法研究饮料中游离钙含量的影响因素及其应用。方法:配制不同浓度钙离子溶液并测定电位值,制作电极的校准曲线,应用该方法测定多种饮料、奶粉及乳清粉中游离钙的含量,并研究饮料中游离钙的回收率、离心对游离钙含量测定以及回收率测定的影响、研究p H值、磷酸盐或柠檬酸盐、多糖对饮料中游离钙含量的影响。结果:钙离子溶液的电位值与浓度的对数值之间呈现较高的线性相关,相关系数达0.99以上,应用校准曲线测定钙离子溶液时回收率达98.4%~100.5%,可以用于高低不同浓度游离钙含量的测定;测定饮料游离钙时离心与否不影响游离钙含量的测定,同时,由于存在螯合剂以及脂肪酸等物质回收率将明显偏低;pH、不同盐及不同盐的浓度、不同多糖明显影响饮料中游离钙的含量。结论:钙离子选择性电极法可以用于饮料及奶粉等粉末样品中游离钙含量的测定,同时,用于饮料中游离钙含量的各种影响因素的研究。     

The effect of calcium dips combined with mild heating of whole kiwifruit for fruit slices quality maintenance

The effect of moderate heat treatment combined with calcium dips on the quality of minimally processed kiwifruit was studied. Whole fruits were treated for 25 min at 45 °C by dipping in deionised water or CaCl₂ solutions (1%, 2% and 3% (w/v)) and cooled to 4 °C. Twenty-four hours later fruits were peeled, sanitized, cut into slices and packed. The firmness of kiwifruit slices’ was subsequently evaluated during 8 days of storage. Calcium content, pectinmethylesterase activity and heat shock proteins accumulation were also investigated. Heat treatment conducted in water induced a firming effect and avoid softening of fruit slices while calcium dips had a marginal effect on this parameter. A calcium loss was observed due to dip treatment, but this effect was minimized when treatment was conducted in 3% CaCl₂ solution. The firming effect provided is due to the activation of pectinmethylesterase and the presence of calcium in treatment solution reduces or inhibits enzyme activation. Under the tested conditions, no heat shock proteins de novo synthesis was detected.