浅析食盐的健康摄入

人们食盐摄入过量,对身体会造成伤害。如何减少食盐的摄入量成为当前健康饮食的当务之急。本文主要介绍了健康食盐的必要性,并对合理摄入食盐作了一定的阐述,     

食盐加碘与人体健康

对食盐加碘与人体健康的关系进行了详尽介绍,具体内容包括食盐加碘的概况,加碘盐的成分、浓度标准、工艺流程、检测方法,碘在人体内的分布及代谢,食盐加碘对人体健康的影响四个方面,以使人们更全面地了解食盐加碘与人体健康的关系。     

食盐加硒与人体健康

硒与人体健康的关系，引起了国内外医学界的极大关注。加硒食盐是解决人群缺硒的最好办法之一。我国在1996年颁布了硒强化食盐的标准(082238-96)，加硒盐其特点是能定量、定时、均衡地供给人体部分的硒，是人体最有效的补硒方法之一。     

食盐粒径对食盐结块的影响探究

食盐结块现象是一个长期以来难以解决的问题,直接影响食盐的生产、销售及使用.文章在试验室条件下从食盐粒径对食盐结块的影响进行了研究,通过试验,验证了食盐粒径对食盐结块的影响,对试验中得出的结果进行了简要分析.     

食盐加铁对人体健康的意义

铁是人们最早发现与人体健康有重要关系的微量元素。自20世纪70年代后，医学界对微量元素在生命过程中的意义、生理功能、代谢过程、缺乏症和中毒症等方面的详细研究、同时对微量元素的检验水平有了进一步提高，到目前为止，锌、铁、铜、锰、牯、钼、硒、铬、碘、氧、锡、硅、钒、镍14种元素。     

食盐每日不可少 过多摄入损健康

人离不开盐，如果没有盐人体便不能维持正常状态。食盐的主要成份是氯化钠。当这种化合物在人体内形成水溶液后，就分解成为钠和氯离子，分别发挥着不同的作用。钠离子能维持人体全身血液容量和细胞渗透压，以及神经与肌肉的正常兴奋和应激性；能激活人体肌肉收缩等多种功能。氯离子则可帮助调节人体的酸碱平衡，生产胃酸和激活淀粉酶，这对于生命是极为重要的。     

食盐的“阴阳效应”

日常饮食要限盐少盐．这一观念如今已逐渐被具有保健意识的人群所接受,并将之视为预防高血压和心血管疾病的一项重要措施。不过,日前英国公布的一项长期跟踪调查则发现,食盐对高血压有“阴阳效应”——其中的钠离子可增加患高血压风险,而氯离子却有利于降低高血压患者的死亡风险。     

食盐替代物研究进展

高血压、心脏病等疾病均与摄入过量的食盐(NaCl)有关.降低钠离了摄入量同时保证咸度的食盐替代物的开发对人们饮食健康具有重要意义.木文主要从开发食盐替代物的必要性出发,对咸味肽、非钠盐类及其他食盐替代物的研究现状进行概述,并对食盐替代物的发展前景作出展望.     

食盐对酱油酿造的影响

文章概述了食盐在酱油酿造中的应用和条件,以及对酱油的影响,体现了食盐在酱油酿造中的重要性。     

Effects of potassium lactate and high pressure on transglutaminase restructured dry-cured hams with reduced salt content

Ten raw hams (from 5 carcasses) were boned and salted either with salt reduction (15 g/kg NaCl) or salt reduction with addition of potassium lactate (15 g/kg NaCl and 39.74 g/kg of a 60% K-lactate solution). Subsequently, the ham pieces were assembled together with transglutaminase, vacuum packed into water-permeable plastic bags and kept at 3 °C and 85% RH until reaching above 30% weight losses. The effects of K-lactate addition and the high-pressure (HP) treatment at 600 MPa on the physicochemical, instrumental colour and texture (Tensile test) and sensory characteristics of the biceps femoris (BF) muscle were evaluated. The addition of K-lactate did not have a negative effect on colour, flavour or texture of restructured dry-cured hams. The HP treatment increased significantly the pH, L^∗, a^∗ and b^∗ values and the breaking stress, and decreased the water-holding capacity and elasticity (apparent Young’s modulus) of BF muscle. The HP treatment also affected significantly the flavour (increasing saltiness, umami and sweetness) and the sensory texture attributes (increasing muscle binding, hardness, gumminess and fibrousness and decreasing adhesiveness and pastiness), as well as slice appearance (increasing brightness and iridescence and decreasing colour homogeneity).     

A longitudinal comparison of two salt reduction strategies: Acceptability of a low sodium food depends on the consumer

In their 2010 publication, Strategies to Reduce Sodium Intake in the United States, the Institute of Medicine suggested the FDA mandate salt reduction at the food industry level via a strategy of gradual, step-wise decline. The objective of this study was to compare the acceptability trajectories of a gradual to an abrupt salt reduction strategy of a high sodium food, and to determine if these trajectories were impacted by an individual’s hedonic sensitivity to salt and/or motivation to reduce dietary salt intake. Eighty-three subjects participated in a three-part study: an initial taste test, a 16-week longitudinal study, and a final taste test. At the initial and final taste tests, subjects indicated liking of tomato juice at four salt concentrations ranging from 136 mg sodium/serving (low sodium) to 640 mg sodium/serving (comparable to a commercially available product). To create two groups for the 16-week study, subjects were balanced for 6-n-propylthiouracil sensitivity, motivation to reduce dietary salt intake, and hedonic sensitivity to salt (the difference in liking between the highest and lowest salt concentrations in tomato juice served at the initial taste test). One group received juice abruptly reduced in salt at week 4 to a target low sodium level; the second group received juice gradually reduced in salt via difference threshold steps determined in a preliminary study (cumulating reductions of 12% each), to reach the target at week 14. We observed no overall difference in liking for low sodium juice at the end of the study as a result of salt reduction strategy; however, the trajectory of liking ratings over time differed between groups. Gradual salt reduction was more effective than the abrupt salt reduction because the abrupt reduction was accompanied by a large immediate drop in liking whereas the gradual reduction better maintained acceptability throughout the process. Subjects with low hedonic sensitivity responded favorably to both salt reduction strategies and would likely have no difficulty in adjusting to the taste of reduced salt foods. However, subjects with high hedonic sensitivity disliked reduced salt juice at some point during the study, regardless of strategy, and would likely have difficulty in adjusting to the taste of reduced salt foods.     

Impact of salt reduction interventions on salt taste sensitivity and liking,a cluster randomized controlled trial

BackgroundExcessive intake of salt is associated with high blood pressure, a risk factor for cardiovascular disease. Moreover, a high salt consumption has been related to a reduced salt taste sensitivity, and an increased liking of high salt content foods. Whether a reduction in salt intake over a long period of time can increase salt taste sensitivity and liking of foods with lower salt content requires further research.ObjectiveThis study aims to investigate the effect of gradually lowering salt content in bread, either alone or in combination with dietary counselling, on salt taste sensitivity and liking of salt reduced bread.MethodsA four-month, single blinded, cluster RCT with a parallel design was conducted among Danish families. Families were randomized to receive bread gradually reduced in salt content (Intervention A), bread gradually reduced in salt content in combination with dietary counselling (Intervention B) or bread with regular salt content (control). Salt taste detection thresholds (DT) and recognition thresholds (RT) were measured at baseline and follow-up. Moreover, overall liking of bread with very low (0.4 g/100 g), low (0.8 g/100 g) and normal (1.2 g/100 g) salt content was measured using a 7-point hedonic scale.ResultsEighty-nine families (n = 215) participated in the study. No significant differences between groups were found for DT or RT, but a significant reduction in DT of 18% (−28, −7) and a trend towards a reduction in RT of −16% (−30, 2) was found in Intervention B from baseline to follow-up. The intervention resulted in significantly higher liking of bread with 0.4 g salt/100 g in intervention B compared to the control and borderline significantly higher liking in intervention A compared to the control (p-value = 0.055). No differences were seen between groups in liking of bread with 0.8 g and 1.2 g salt/100 g. From baseline to follow-up all three groups reduced their liking of bread with 1.2 g salt/100 g and in the control group liking of bread with 0.4 g salt/100 g was significantly reduced.ConclusionReducing salt intake by lowering salt content in bread and receiving dietary counselling increased salt taste sensitivity (baseline to follow-up) and resulted in higher liking of bread with very low salt content (0.4 g salt/100 g) compared to control.     

Sensory and texture properties of Italian typical dry-cured hams as related to maturation time and salt content

Maturing time and salt were fixed factors and fat was a covariate in a full factorial design study of sensory and texture properties of 36 dry cured hams. Samples were chosen to fit three ageing and salt classes. Differences (P < 0.05) in sensory scores were found between whole slices (with cover fat) and their biceps femoris (BF) counterparts, with sweet taste enhanced in whole samples and conversely unpleasant bitter taste more intense in BF portions. Increased ageing time resulted in better sensory profiles, as documented by greater scores (P < 0.05) for matured odour, matured taste and sweet taste, whereas salty taste was reduced. Decreased salt was associated with greater intensities (P < 0.05) of undesired green odour and taste. Based on chemical composition, the ham consistence appears improved by long-term dehydration, provided that protein breakdown is under control. It is concluded that for salt reduction of up to 25% to be achieved without negative side effects, extended ageing and restrained proteolysis are key factors.     

The effect of NaCl-free processing and high pressure on the fate of Listeria monocytogenes and Salmonella on sliced smoked dry-cured ham

NaCl is an important multifunctional ingredient applied in dry-cured ham elaboration. However, its excessive intake has been linked to serious cardiovascular diseases causing a recent increase in the development of reduced salt products. In the present study Listeria monocytogenes and Salmonella, food-borne pathogens which can cross-contaminate post processed products, were spiked with < 100 CFU/g on slices of both standard (S) and NaCl-free processed (F) (elaborated with KCl + potassium lactate instead of NaCl) smoked dry-cured ham. Although L. monocytogenes and Salmonella counts decreased faster in S ham, pathogens were present in both types of non-pressure treated ham during the entire refrigerated storage period (112 days). Pressurisation at 600 MPa for 5 min caused the elimination of both pathogens in S ham after 14 days. In contrast, Salmonella and L. monocytogenes were present in F ham until days 28 and 56, respectively, indicating that the NaCl-free processed dry-cured ham had lower stability than standard smoked dry-cured ham.     

Influence of NaCl concentration and high pressure treatment on thermal denaturation of soybean proteins

In the present work the effect of high pressure (HP) treatment in the presence of NaCl on the thermal behavior of soybean proteins was analyzed by differential scanning calorimetry. The thermograms obtained have shown that NaCl addition increased the thermal stability – increase in temperatures of denaturation (Td) – of both glycinin and β-conglycinin. HP treatments increased thermal stability of glycinin, but decreased that of β-conglycinin. High NaCl concentrations decreased (in glycinin) or inverted (in β-conglycinin) the effects of HP on thermal stability. Cooperativity of denaturation of glycinin was enhanced by NaCl and HP. Cooperativity of denaturation of β-conglycinin was enhanced by HP and also by NaCl at 0.2 mol/L but decreased with the combination of treatments. Salt addition increased the enthalpy, ΔH, of denaturation of glycinin and β-conglycinin, being this effect stronger on glycinin. HP treatment provoked the denaturation of both protein fractions. The presence of NaCl protected glycinin against HP-denaturation at any assayed salt concentration and pressure level, while β-conglycinin was only protected at 200 and 400 MPa, but was more denaturated at 600 MPa in the presence of 0.6 mol/L of NaCl.

Industrial relevance

The knowledge provided by this work may be useful in the handling of high pressure-treated food with high NaCl content (e.g. meat emulsions, smallgoods) where soybean proteins are used as additives, in order to choose high pressure values to achieve their denaturation or predict the effects of ulterior thermal treatments. Thus, this knowledge may be useful to increase the use of high pressure in food industry.     

Reducing salt in imitation cheese: Effects on manufacture and functional properties

Imitation cheeses (48% moisture, 0-1.5% NaCl) were manufactured using a Farinograph or Blentech cooker. The effects of NaCl reduction on cheese manufacture, functionality (assessed by texture profile analysis, flowability, dynamic rheology and microscopy), microbiological stability and sensory attributes were investigated. Reducing NaCl concentration decreased processing times and mixing energy required during manufacture and, post-manufacture, decreased cheese hardness, G′ values at 25 °C and crossover temperature and increased fat globule size. Cheeses from both cookers showed the same trend in functionality. Microbial stability was reduced at 0% NaCl, and the sensory panellists preferred the 50% reduced NaCl cheese to the standard.     

Effects of microbial transglutaminase and sodium alginate on cold-set gelation of porcine myofibrillar protein with various salt levels

The effects of microbial transglutaminase (TG) and sodium alginate (SA) systems on cold-set gelation of myofibrillar protein (MP) at various salt levels were investigated. The gelation kinetics data showed that both TG and SA had optimal but different salt levels to form an acceptable cold-set MP gel. Although their gelling characteristics were altered with different salt levels, the combination of TG and SA showed a rapid cold-set MP gel formation, regardless of salt levels. The effect of TG and SA on gel strength was reversed by increasing the salt level, while the cold-set MP gel strength of the TG and SA combination was not affected by salt levels. Furthermore, the SA system contributed to improved water-binding ability and cold-set MP gel formation, while the TG system enhanced the gel strength of the MP after cooking at low-salt levels. In addition, TG's effects on gel strength of MP increased at higher salt levels, the SA system prevented the moisture loss induced by the TG reaction. There was no evidence of any interaction between SA and MP in the thermogram and gel electrophoresis data. Results from this study suggested that a system combining TG with SA had the potential advantage of improving the water-binding ability and producing cold-set MP gelation at an even lower salt level than TG alone.     

The effect of high hydrostatic pressure,sodium nitrite and salt concentration on the growth of Listeria monocytogenes on RTE ham and turkey

Growth of Listeria monocytogenes was evaluated for up to 182 days after inoculation on ready-to-eat (RTE) sliced ham and turkey breast formulated with sodium nitrite (0 or 200 ppm), sodium chloride (1.8% or 2.4%), and treated (no treatment or 600 MPa) with high hydrostatic pressure (HHP). HHP at 600 MPa for 3 min resulted in a 3.85–4.35 log CFU/g reduction in L. monocytogenes. With formulations at similar proximate analyses, one of the evaluation days (day 21) without HHP showed significantly greater growth of L. monocytogenes in ham than in turkey breast, but there were no significant differences on other evaluation days or with HHP. There were no differences in growth of L. monocytogenes due to sodium chloride level. Sodium nitrite provided a small, but significant inhibition of L. monocytogenes without HHP, but addition of sodium nitrite did not significantly affect growth of L. monocytogenes with use of HHP.     

温度和盐胁迫对油葵种子萌发及幼苗生长的影响

通过测定不同温度和盐胁迫浓度对油葵种子发芽势、发芽率和幼苗生理生化特性指标的影响,发现相同温度条件下,随着盐浓度的升高,油葵种子的发芽势、发芽率呈降低趋势,发芽时间延迟,胚根的生长受到抑制,胚根长、子叶鲜重均呈现下降的趋势;油葵幼苗的叶片和根系的电解质相对外渗率,SOD、POD活性均呈现先升后降的趋势。相同浓度盐胁迫下,油葵种子的发芽势和发芽率随温度的升高而升高,表现出喜温的特性,说明油葵种子在萌发阶段,适宜的高温条件有利于其种子发芽,幼苗对盐胁迫也有较强的适应能力。