A study on the implications of NaCl reduction in the fermentation profile of Conservolea natural black olives

This study examined the impact of different mixtures of NaCl, KCl, and CaCl₂ on the fermentation profiles of Conservolea natural black olives. Five different combinations of chloride salts were investigated, namely (i) 8% NaCl (control treatment), (ii) 4% NaCl and 4% KCl, (iii) 4% NaCl and 4% CaCl₂, (iv) 4% KCl and 4% CaCl₂, and (v) 2.6% NaCl-2.6% KCl-2.6% CaCl₂. The changes in the microbial association (lactic acid bacteria, yeasts, Enterobacteriaceae), pH, titratable acidity, organic acids, volatile compounds, and mineral content in olive flesh were analyzed. Results demonstrated that all salt combinations led to vigorous lactic acid processes based on the obtained values of pH (3.9-4.2) and titratable acidity (0.70-0.86 g lactic acid per 100 ml brine). Organoleptic evaluation was a critical factor in the acceptability of the final product. Increasing concentrations of CaCl₂ or a combination of KCl and CaCl₂ rendered the product bitter with low acceptability by the taste panel. Only one combination of chloride salts (4% NaCl and 4% KCl) could finally produce olives with lower sodium content and good organoleptic attributes. The results of this study could be employed by the Greek table olive industry in an attempt to produce natural black olives with less sodium without affecting the traditional taste of fermented olives in order to meet consumers’ demand for low sodium dietary intake.     

Chloride salt mixtures affect Gordal cv. green Spanish-style table olive fermentation

This work studies the effects of different sodium (in the range of 4-10%), potassium (0-4%) and calcium (0-6%) chloride salt mixtures on the fermentation profile of Gordal olives processed according to the Spanish style. For this purpose, response surface methodology based on a simplex centroid mixture design with constrain (sum of salt percentages = 10%) was used. All treatments reached appropriate titratable acidity levels, but this parameter could not be related to the initial chloride salt concentration. The presence of CaCl₂ led to lower initial and after-fermentation pHs, delayed sugar diffusion into the brine, its maximum concentration and titratable acidity formation. CaCl₂ also delayed Enterobacteriaceae and yeast sprang, decreasing their overall growth. This chloride salt also showed a tendency to reduce overall lactic acid bacteria growth. KCl had a similar behaviour to NaCl but, in general, increased overall microbial growth. Thus, a partial substitution of NaCl in Spanish-style green olives with KCl and CaCl₂ does not substantially modify the fermentation profile but does produce some changes, which, when properly managed, could help to improve product processing.     

Mineral content and sensory characteristics of Gordal green table olives fermented in chloride salt mixtures

This work studies the effects of the initial brine concentrations of NaCl, KCl, and CaCl(2) on the mineral content and gustatory and kinaesthetic sensations of fermented green table olives, using a simplex centroid mixture design augmented with interior points. The sodium in the flesh was linearly related to the mixture concentrations while potassium and calcium were linked by quadratic and special cubic models respectively. Acidity, saltiness, hardness, fibrousness, and crunchiness were expressed as linear funtions of the NaCl, KCl, and CaCl(2) initial brine contents but bitterness required quadratic equations. The models can be used to produce table olives with specific mineral contents in the flesh and to predict their corresponding sensory characteristics. PRACTICAL APPLICATION: The study provides the industry with models to estimate the Na, K, and Ca mineral contents in the flesh of fermented Gordal green table olives as well as their sensory characteristics as a function of the NaCl, KCl, and CaCl(2) initial compositions in the brining solution. Therefore, the paper provides tools which are able to support the production of commercial presentations which not only satisfy consumer demand for low Na, but are also K and Ca fortified table olive presentations with specific sensory profiles.     

Fermentation profiles of Manzanilla-Aloreña cracked green table olives in different chloride salt mixtures

NaCl plays an important role in table olive processing affecting the flavour and microbiological stability of the final product. However, consumers demand foods low in sodium, which makes necessary to decrease levels of this mineral in fruits. In this work, the effects of diverse mixtures of NaCl, CaCl₂ and KCl on the fermentation profiles of cracked directly brined Manzanilla-Aloreña olives, were studied by means of response surface methodology based in a simplex lattice mixture design with constrains. All salt combinations led to lactic acid processes. The growth of Enterobacteriaceae populations was always limited and partially inhibited by the presence of CaCl₂. Only time to reach half maximum populations and decline rates of yeasts, which were higher as concentrations of NaCl or KCl increased, were affected, and correspondingly modelled, as a function of salt mixtures. However, lactic acid bacteria growth parameters could not be related to initial environmental conditions. They had a longer lag phase, slower growth and higher population levels than yeasts. Overall, the presence of CaCl₂ led to a slower Enterobacteriaceae and lactic acid bacteria growth than the traditional NaCl brine but to higher yeast activity. The presence of CaCl₂ in the fermentation brines also led to higher water activity, lower pH and combined acidity as well as a faster acidification while NaCl and KCl had fairly similar behaviours. Apparently, NaCl may be substituted in diverse proportions with KCl or CaCl₂ without substantially disturbing water activity or the usual fermentation profiles while producing olives with lower salt content.     

Effect of sodium chloride replacement on some characteristics of fermented sausages

The reduction of added NaCl in fermented meat products has been proposed to decrease the amount of sodium in the diet. The effect of substituting NaCl by KCl, potassium lactate (K-lactate) or glycine (0-40%) in some sensory, microbiological and physicochemical characteristics of fermented sausages was evaluated. The sensory effects of substituting NaCl by mixtures of glycine and KCl or glycine and K-lactate was also evaluated. The partial substitution of NaCl by KCl, K-lactate and glycine had little effect on microbiological stability. However, flavour and/or textural defects were detected by sensory analysis with substitution levels of 40% by KCl, 30% with K-lactate and 20% with glycine. The partial substitution (above 40%) of NaCl with different mixtures of KCl/glycine and K-lactate/glycine showed important flavour and textural defects which did not permit an increase in the level of substitution compared to those obtained with the individual components.     

Enrichment of table olives with polyphenols extracted from olive leaves

The possibility to increase the nutritional value of table olives using polyphenols extracted from olive leaves was studied. Leaves were subjected to extraction using water with proportions of 1%, 5% and 10% of leaves and various temperatures and times (room temperature/24 h, 40 °C/10 min and 70 °C/5 min). The antioxidant activity of extracts was determined using the Rancimat method and their content in oleuropein and hydroxytyrosol was determined by HPLC. The extract with the highest antioxidant activity and polyphenol content (10% ratio of olive leaves extracted at room temperature for 24 h) was used for the treatment of debittered table olives. The treated and untreated olives were subjected to determination of their α-tocopherol, oleuropein and hydroxytyrosol content. A 457% increase was observed for oleuropein and 109% for hydroxytyrosol content after treatment. Sensory evaluation of treated table olives showed an increase in bitterness. However, treated and untreated table olives showed equal overall acceptability and overall preference.     

Olive Fermentation and Processing: Scientific and Technological Challenges

ABSTRACT: The 3 main commercial table olive preparations are the Spanish-style green olives, the Greek-style naturally black olives, and the Californian-style black ripe olives. In all cases, fruits undergo fermentation in brine solution, which preserves them and increases palatability. Lactic acid bacteria dominate in brines of green olives, while mainly fermentative yeasts are found in brines of black ones. The fermentation is spontaneous and begins as soon as olives are put into brine. Research on table olives has been going on for 100 years, but many questions remain. Previous work has focused on the efficient utilization of starter cultures in order to control the fermentation, to guarantee the absence of spoilage, and to govern the relationship between olive flavor and microorganisms. Nowadays, there is concern over environmental problems that the fermentation solutions represent, in particular their high NaCl content. Fermentation or simply storing olives in water without salt presents some problems. The high concentration of sodium benzoate used for storing black ripe olives by the American industries is not advisable for European processes due to the residual amount of preservative in the final product. Fermentation of green olive wash waters, in order to obtain valuable products, is being pursued, but polymeric inhibitors are problematic and undesirable microorganisms grow. The consumption of organic foods is increasing and black olives fit the definition since they are processed without chemical treatment. However, the hydrolysis of the bitter compound oleuropein, either by microorganisms or acids, needs to be studied.     

Effect of chloride salt mixtures on selected attributes and mineral content of fermented cracked Aloreña olives

Sodium chloride is essential in table olive fermentation, storage and packing to guarantee safety and flavor. However, consumers are progressively concerned about sodium intake. In this work, the effect of selected attributes and mineral contents of fermented cracked Aloreña olives as a function of different chloride salt mixtures were studied, using a simplex lattice design with constrains (NaCl + CaCl₂ + KCl = 0.110 kg/l). The best fruit colour was observed at half proportions of KCl and NaCl or CaCl₂; optimum firmness was around the centre of the triangular coordinates but close to the line connecting CaCl₂ and NaCl vertexes; and the best overall quality was obtained in the 0.037 kg/l NaCl and 0.073 kg/l KCl mixture. The concentrations in the fermented olive flesh of the involved elements depended on their initial levels and on the CaCl₂ × NaCl and CaCl₂ × KCl interactions. Results demonstrate that sodium chloride can be replaced in table olives, at least partially, with potassium or calcium chlorides.     

Manufacture of low-sodium Minas fresh cheese: effect of the partial replacement of sodium chloride with potassium chloride

We investigated the effect of sodium reduction by partial substitution of sodium chloride (NaCl) with potassium chloride (KCl) on the manufacture of Minas fresh cheese during 21 d of refrigerated storage. Four treatments of low-sodium Minas fresh cheese were manufactured, with partial replacement of NaCl by KCl at 0, 25, 50, and 75% (wt/wt), respectively. The cheeses showed differences in the content of moisture, ash, protein, salt, and lipid contents, as well as on the extent of proteolysis and hardness throughout the storage period. However, no difference was observed among treatments within each storage day tested. The partial substitution of NaCl by KCl decreased up to 51.8% the sodium concentration of the cheeses produced. The consumer test indicated that it is possible to manufacture a low-sodium Minas fresh cheese that is acceptable to consumers by partial substitution of NaCl by KCl at 25% (wt/wt) in the salting step.     

Proteolysis in reduced sodium Feta cheese made by partial substitution of NaCl by KCl

Feta cheeses (five trials) of different sodium content were made, using ewes’ milk, from split lots of curd by varying the salting procedure, i.e. dry salting with NaCl (control) or mixtures of NaCl/KCl (3:1 or 1:1, w/w basis) and filling the cans with brine made with NaCl or the above NaCl/KCl mixtures, respectively, in order to study the influence of the partial substitution of NaCl by KCl on the proteolysis during cheese ripening. The extent and characteristics of proteolysis in the cheeses were monitored during aging by using Kjeldahl determination of soluble nitrogen fractions (water-soluble nitrogen, trichloroacetic acid-soluble nitrogen, phosphotungstic acid-soluble nitrogen), the cadmium–ninhydrin method for the determination of total free amino acids (FAA), urea–polyacrylamide gel electrophoresis of cheese proteins followed by densitometric analysis of the α_s1- and β-casein fractions, reverse-phase HPLC analysis of the water-soluble extracts of cheeses, and ion-exchange HPLC analysis of FAA. The results showed that proteolysis was similar in control and experimental cheeses at all sampling ages, indicating that the partial substitution of NaCl by KCl in the manufacture of Feta cheese had no significant effect on the extent and characteristics of proteolysis during cheese aging.     

KCl部分替代NaCl对猪肉脂肪氧化的动力学影响

为探究KCl部分替代NaCl对猪肉加工中脂肪氧化的影响,以绞碎的猪背最长肌为原料,加入3％或4％的盐,并分别以15％、30％、45％和60％的KCl替代NaCl,经不同温度处理后,研究脂肪氧化的动力学变化.结果表明,当盐的组成和含量不变时,脂肪初级及次级氧化速率常数均随温度的增加而增加.当温度不变时,脂肪初级氧化速率常...     

INFLUENCE OF SALTS AND pH ON THE FIRMNESS OF OLIVES IN ACID CONDITIONS

The effects of NaCl and CaCl₂ on the texture of olives, both treated and untreated with NaOH, at pH values lower than 4.0 were determined. Firmness of green olives declined as the pH decreased when calcium ions were not added. Calcium ions inhibited the softening rate of fresh and Spanish style green olives although this inhibitory effect depended on the pH. This firming action of calcium was higher at lower pH for fresh olives and at higher pH values for Spanish style green olives. The inhibitory effect of calcium on softening rate diminished as the concentration of cation increased. The presence of NaCl did not have any effect on the texture of either type of green olives. Lactic acid increased the softening rate of green olives by a higher proportion than acetic acid.     

Biochemical changes in dry-cured loins salted with partial replacements of NaCl by KCl

The effect of partial replacement of NaCl by KCl in the dry-curing of loins has been evaluated by biochemical and sensory analysis of the final products. Endoproteolytic enzymes like cathpesins B and B + L appeared to be more active when more KCl and less NaCl were present in the curing salt while cathepsin H remained unaffected. Proteolysis was reflected by SDS–PAGE in the higher density of the sarcoplasmic proteins bands within the range 55.0–28.0 kDa. Alanyl aminopeptidase (AAP) was unaffected while arginyl and leucyl aminopeptidases were more activated by KCl. On the other hand, methionyl aminopeptidase and dipeptidylpeptidase I and III were more inhibited as KCl increased in the curing salt blends. The sensory analysis revealed no significant differences between control loins with 100% NaCl and those with up to 50% of KCl substitution. Furthermore, loins elaborated with 50% of each salt obtained the highest scores.     

不同KCl和NaCl组成的减盐配方对卤鸭制品品质特性的影响

以鸭腿（肉鸭腿、老鸭腿）为原料,以普通食盐组为对照,研究KCl部分替代NaCl（A1组： NaCl∶KCl=80∶20;A2组：NaCl∶KCl=75∶25;A3组：NaCl∶KCl=70∶30;A4组：NaCl∶KCl=65∶35;A5组： NaCl∶KCl=60∶40）对卤鸭产品品质特性指标和感官评价的影响,确定最优减盐卤鸭制品的配方。结果表明：与普 通食盐组卤鸭制品相比,KCl的替代比例为35%时对不同减盐配方组卤鸭制品的感官评价、电子舌分析指标、蒸煮 损失、剪切力、水分含量、pH值、蛋白质含量、脂肪含量以及灰分含量没有显著影响（P＞0.05）;KCl的替代比 例达到35%及以上时,对卤鸭制品的水分活度有显著影响（P＜0.05）。确定A4组为最优的卤鸭减盐配方,以100 g 卤鸭原料计,优化所得配方为腌制时NaCl∶KCl=65∶35;以100 g卤汤计,卤制时卤汤中NaCl∶KCl=65∶35。     

KCl部分替代NaCl腌制对风干鲈鱼中生物胺的抑制作用

用不同比例的KCl部分替代NaCl腌制,在15 ℃、80%～90%相对湿度条件下风干成熟84 h得风干鲈鱼产品。通过测定产品中理化指标、挥发性盐基氮、生物胺含量以及感官品质的变化,研究KCl部分替代NaCl对风干鲈鱼中生物胺的抑制作用。风干鲈鱼产品中共检测到6种生物胺,分别为：腐胺、尸胺、组胺、酪胺、精胺、亚精胺。当KCl替代比例从0%增大到50%,产品中生物胺总含量先下降后上升。当KCl替代比例为20%时,风干鲈鱼产品中生物胺总含量达到最低值192.17 mg/kg,比对照组（KCl含量为0%）降低62.90%;同时,腐胺、尸胺、组胺含量的减少量分别为76.94%、84.68%、54.46%。感官分析结果表明,当KCl替代比例不超过40%时风干鲈鱼产品的感官品质未有明显变化。以上结果表明在保持风干鲈鱼原有感官品质的基础上,用KCl部分替代NaCl腌制可以显著抑制（P＜0.05）产品中生物胺的形成。     

Biochemical and sensory changes in dry-cured ham salted with partial replacements of NaCl by other chloride salts

The reduction of the content of sodium chloride in dry-cured ham was studied in to prevent the problems related to high sodium intake (i.e. the hypertension). One of the possibilities to reduce the sodium content is the partial replacement of sodium chloride by mixtures of potassium, magnesium and calcium chloride salts. The effect of two salting formulations (formulation II: 50% NaCl-50% KCl and formulation III: 55% NaCl, 25% KCl, 15 CaCl₂ and 5 MgCl₂) on the protease activity through the dry-curing process and on the sensory characteristics of the final product was evaluated and compared to those of control hams (formulation I, 100% NaCl). Sensory attributes were all affected in the hams containing CaCl₂ and MgCl₂ while hams containing 50% KCl and NaCl (formulation II) were better valued, except for the attribute taste probably due to the potassium contribution to bitter taste.     

Individual effects of sodium, potassium, calcium, and magnesium chloride salts on Lactobacillus pentosus and Saccharomyces cerevisiae growth

A quantitative investigation on the individual effects of sodium (NaCl), potassium (KCl), calcium (CaCl2), and magnesium (MgCl2) chloride salts against Lactobacillus pentosus and Saccharomyces cerevisiae, two representative microorganisms of table olives and other fermented vegetables, was carried out. In order to assess their potential activities, both the kinetic growth parameters and dose-response profiles in synthetic media (deMan Rogosa Sharpe broth medium and yeast-malt-peptone-glucose broth medium, respectively) were obtained and analyzed. Microbial growth was monitored via optical density measurements as a function of contact time in the presence of progressive chloride salt concentrations. Relative maximum specific growth rate and lag-phase period were modeled as a function of the chloride salt concentrations. Moreover, for each salt and microorganism tested, the noninhibitory concentrations and the MICs were estimated and compared. All chloride salts exerted a significant antimicrobial effect on the growth cycle; particularly, CaCl2 showed a similar effect to NaCl, while KCl and MgCl2 were progressively less inhibitory. Microbial susceptibility and resistance were found to be nonlinearly dose related.     

Characterisation of an oleuropein degrading strain of Lactobacillus plantarum. Combined effects of compounds present in olive fermenting brines (phenols,glucose and NaCl) on bacterial activity

This study aims to examine the effects of glucose and NaCl on the ability of an oleuropein degrading strain of Lactobacillus plantarum, strain B21, to grow in the presence of oleuropein, its degradation product, hydroxytyrosol, and p-coumaric acid. Oleuropein (10 g litre⁻¹) and 2 g litre⁻¹ hydroxytyrosol combined with NaCl did not inhibit bacterial growth, whereas 1 g litre⁻¹ p-coumaric acid showed low inhibitory activity. This study also presents that bacterial β-glucosidase and esterase are involved in the breakdown of oleuropein. Oleuropein (10 g litre⁻¹) incorporated in the cultivation medium without glucose was completely degraded to derivative products within 20 days, whereas in the presence of glucose, at concentrations up to 50 g litre⁻¹ β-glucosidase activity was partially inhibited, and 30–70% of oleuropein residual content remained in the cultivation medium. Esterase activity involved in the second step of biodegradation process, was not influenced by glucose. Incorporation of glucose in the growth medium adversely affected the ability of L plantarum to break-down oleuropein. The findings of this study are significant since it could lead to the development of a new biotechnology for removing the bitter principle, oleuropein, from olives replacing the traditional alkali treatment used for debittering olives. © 1998 SCI.     

Stability of monosodium glutamate in green table olives and pickled cucumbers as a function of packing conditions and storage time

The effects of different packing conditions and storage times on the stability of monosodium glutamate (MSG) added to two different fermented vegetables (Spanish-type green table olives and pickled cucumbers) were studied. Factors such as packaging material (glass bottle versus plastic pouch), heat treatment (pasteurisation versus non-pasteurisation), and the presence or not of a preservative compound (potassium sorbate) were considered. The MSG content of pickled cucumbers was stable for up to 1 year of storage in all packing conditions studied. The MSG content also remained stable in pasteurised green table olives. On the contrary, MSG was extensively degraded (>75% degradation) after 54 weeks of storage in unpasteurised green olives with a higher degradation rate in glass bottles compared with plastic pouches. In the presence of potassium sorbate, MSG was also considerably degraded in olives packed in plastic pouches (>50% degradation), but hardly degraded in glass bottles. The results indicate that MSG degradation in olives is due to the action of both lactic acid bacteria and yeasts, with the formation of γ-aminobutyric acid as the major end-product.