DETERMINING SEQUENTIAL DIFFERENCE THRESHOLDS FOR SODIUM CHLORIDE REDUCTION

Effect of Steaming and Microwave Heating on Taste of Clear Soup with Split-Gill Mushroom Powder

Salt is widely overconsumed. Among the strategies used in low-salt foods, the addition of flavor enhancers to improve saltiness perception through an umami taste is a viable and promising technique. This study investigated using split-gill mushroom (SGM) powder containing umami taste to increase saltiness in a clear soup for two different heating conditions: steaming under high pressure and microwave heating. According to the E-tongue results, the addition of 0.2-0.8% SGM produced a different taste in the soup compared to the addition of salt, and the addition of 0.2-0.8% SGM yielded a similar taste to the addition of 0.4-0.6% MSG in a plain, clear soup. In flavored soup, SGM at a high concentration had a taste-enhancing impact comparable to 0.4% MSG, whereas SGM at a low concentration had no taste-enhancing effect. The flavored soups containing 0.4 or 0.8% SGM consisted of two umami 5'-nucleotides: adenosine 5'-monophosphate (5'-AMP) and guanosine 5'-monophosphate (5'-GMP); however, inosine 5'-monophosphate (5'-IMP) was not detected. The major umami amino acids were glutamic acid, aspartic acid, and arginine. Microwave heating increased the salinity and total nucleotides and could maintain the umami amino acids, whereas aspartic acid (one of the umami amino acids) was reduced by 8.23% after steaming under high pressure. Thus, after microwave heating and steaming under high pressure, the equivalent umami concentration was reduced by 43.11 and 44.53%, respectively. In conclusion, the addition of SGM and volumetric heating using microwaves could be an alternative method for reducing the amount of salt in soup by increasing the umami taste intensity and salinity.

Sodium Reduction in Bouillon: Targeting a Food Staple to Reduce Hypertension in Sub-saharan Africa

Bouillon cubes are a staple ingredient used in Sub-saharan African countries providing flavor enhancement to savory foods. Bouillon has been identified as a vehicle for fortification to overcome micronutrient deficiencies in Sub-saharan Africa. However, bouillon has a high sodium content (and in addition with other foods) contributes to dietary sodium intake above recommended guidelines. High dietary sodium intake is a key risk factor for hypertension and cardiovascular disease (CVD). Africa has the highest rates of hypertension and CVD globally with nearly half the adult population above 25 years affected. This review presents current state of research on sodium reduction strategies in bouillon. The key challenge is to reduce sodium levels while maintaining optimal flavor at the lowest possible production cost to ensure bouillon continues to be affordable in Sub-saharan Africa. To produce lower sodium bouillon with acceptable flavor at low cost will likely involve multiple sodium reduction strategies; direct reduction in sodium, sodium replacement and saltiness boosting flavor technologies. Efforts to reduce the sodium content of bouillon in Sub-saharan Africa is a worthwhile strategy to: (i) lower the overall sodium consumption across the population, and (ii) deliver population-wide health benefits in a region with high rates of hypertension and CVD.

Repeated Exposure to Low-Sodium Cereal Affects Acceptance but Does not Shift Taste Preferences or Detection Thresholds of Children in a Randomized Clinical Trial

BACKGROUND

Although salt taste preference is malleable in adults, no research to date has focused on children, whose dietary sodium intake exceeds recommended intake and whose salt taste preferences are elevated.

OBJECTIVE

This proof-of-principle trial determined whether 8-wk exposure to low-sodium cereal (LSC) increased children's acceptance of its taste and changed their salty and sweet taste preferences.

METHODS

Children (n = 39; ages 6-14 y; 67% female) were randomly assigned to ingest LSC or regular-sodium cereal (RSC) 4 times/wk for 8 wk. The cereals, similar in sugar (3 g/cup compared with 2 g/cup) and energy content (100 kcal/cup) yet different in sodium content (200 mg sodium/cup compared with 64 mg sodium/cup), were chosen based on taste evaluation by a panel of children. Mothers completed daily logs on children's cereal intake. At baseline and after the exposure period, taste tests determined which cereal children preferred and measured children's most preferred amount of salt (primary outcomes), and most preferred amount of sucrose and salt taste detection thresholds (secondary outcomes). Repeated measures ANOVAs were conducted on primary and secondary outcomes, and generalized estimating equations were conducted on amount of cereal ingested at home over time.

RESULTS

Both treatment groups accepted and ate the assigned cereal throughout the 8-wk exposure. There were no group × time interactions in salt detection thresholds (P = 0.32) or amount of salt (P = 0.30) and sucrose (P = 0.77) most preferred, which were positively correlated (P = 0.001). At baseline and after the exposure, the majority in both groups preferred the taste of the RSC relative to LSC (P > 0.40).

CONCLUSIONS

Children showed no change in salt preference but readily ate the LSC for 8 consecutive weeks. Findings highlight the potential for reducing children's dietary salt intake by incorporating low-sodium foods in the home environment without more preferred higher-salt versions of these foods. This trial was registered at clinicaltrials.gov as NCT02909764.

Sodium Threshold in Model Reduced and Low Fat Oil-in-Water Emulsion Systems

Sodium and fat reduction in the diet are key factors in the nutrition management of hypertensive individuals. Several reduced and lower fat foods have higher amounts of sodium than their regular fat counterparts, which contradict sodium and fat reduction goals for hypertensive individuals. The objective of this research was to determine the threshold of sodium in a model reduced and low fat oil-in-water emulsion system analogous to salad dressings, so as to identify a reduction level of sodium that may not compromise consumer acceptability. Thirty panelists used the R-index by rating method to evaluate a model reduced fat emulsion system with 7 sodium concentrations (175, 200, 230, 265, 305, and 350 mg) and a model low fat emulsion system with 6 sodium concentrations (160, 170, 180, 190, and 200 mg). For both emulsion systems, 30 g servings of each concentration were presented to panelists. Panelists received 10 replicates of noise and signal samples for both fat levels. The group sodium threshold for the reduced and low fat emulsions was 241.11 and 183.56 mg, respectively. Results indicate saltiness perception is increased when fat content is decreased, and threshold for sodium in the reduced fat emulsion system is higher than the low fat emulsion system with lower fat content. Study findings show opportunities for sodium reduction in reduced and low fat food emulsion systems, particularly additional reductions of sodium without consumer detection.

PRACTICAL APPLICATION

Study results demonstrated sodium difference thresholds for the reduced and low fat emulsions were at levels lower than the mean sodium content found in comparable processed food emulsion systems. Results indicate sodium content can potentially be decreased in reduced and lower fat food emulsion systems without consumer detection. Having insight for where consumers are able to detect a difference in sodium levels within reduced and low fat food systems can contribute to a successful reduction of sodium in reduced and lower fat food systems and benefit individuals requiring reductions of sodium and fat in processed food systems.

Shifting human salty taste preference: Potential opportunities and challenges in reducing dietary salt intake of Americans

Dietary salt reduction of Americans has been a focus of public health initiatives for more than 40 years primarily due to the association between high salt intake and development of hypertension. Despite past efforts, salt intake of Americans has remained at levels well above dietary recommendations, likely due in part to the hedonic appeal of salty taste. As such, in 2010 the Institute of Medicine suggested a strategy of gradual salt reduction of processed foods, the primary source of Americans' dietary salt intake, via an approach intended to minimize impact on consumer acceptability of lower-sodium foods. This brief review discusses the ontogeny and development of human salt taste preference, the role of experience in shifting salt preference, and sources of dietary salt. Our current understanding of shifting human salt taste preference is discussed within the context of potential opportunities for success in reducing dietary salt, and gaps in the research that both limit our ability to predict effectiveness of gradual salt reduction and that need be addressed before a strategy to shift salt preference can realistically be implemented.