Low Sodium Neapolitan Pizza Prepared With Seawater: Nutritional Properties, Sensory Characteristics, Metabolic Effects
Condition: Satiety Response; Carbohydrate Metabolism; Sodium Retention
MeSH terms: Hypernatremia
Study type: Interventional

Summary: 
      Seawater is rich in minerals which may help confer good palatability to foods, favouring the
      use of smaller amounts of salt, a recognized measure of cardiovascular prevention. The aim of
      this study is to investigate the nutritional properties, sensory characteristics and
      metabolic effects of a typical Neapolitan pizza prepared with seawater (SWP) in place of
      common salt, in comparison with Standard traditional Pizza (StP). Methods: The nutritional
      characteristics and the chemical profile of the SWP and StP were assessed by chemical
      analyses and the use of Food Composition Tables. Twelve healthy volunteers will be recruited
      for a Randomized Controlled Trial, with the consumption of one StP and one SWP using a
      balanced crossover design. The satiating power and palatability of the two pizzas will be
      tested by the administration of Visual Analogue Scales. Serum glucose, insulin and sodium
      will be measured every 30 minutes and 3-hour urines will be collected after each meal.
    

Detailed description: 
      The aim of the present study is testing the nutritional properties, the sensory
      characteristics and the metabolic effects of a novel recipe of Neapolitan pizza featuring the
      substitution of common salt with commercial seawater in such proportion as to reduce the
      total amount of sodium chloride in the otherwise traditional dough by approximately 50%.

      The dough for both StP and SWP will be prepared from 170 g of organic flour (Agguggiaro and
      Figna 5 stagioni, 80% type 00/20% type 1, Curatolo, Padova, Italy) with the addition of 110
      mL of tap water or commercial seawater respectively. To the StP 0.05 g of brewer's yeast and
      5 g of unrefined salt (Sale Vero, Oro di Sicilia Srl, Nubia di Paceno, Trapani, Italy) will
      be added, while only 0.02 g of yeast and no salt were added to the SWP. Because salt is known
      to reduce the fermentation rate, based on the calculation that the amount of sodium chloride
      in SWP would be approximately one half of the StP content, it was decided to use
      approximately half the amount of yeast while maintaining constant the fermentation time,
      which was 15 h for both doughs. Commercial seawater is supplied by Steralmar Srl (Bisceglie,
      BT, Italia).

      The trial is conceived as a double blind balanced randomised crossover trial, where each
      subject acted as his/her own control by consuming the two different pizzas at one week
      elapsed time from one another according to a balanced randomised sequence. The trial was
      approved by the Ethical Committee of the University of Naples Federico II (n. 403.20).

      The participants will sign an informed consent to participate and receive detailed written
      instructions by a trained researcher about the study protocol: avoid any intense physical
      activity and complete the evening meal by 9 pm on the day before the test; have a standard
      breakfast (explained in detail) before 8.30 on the morning of the test; drink at least 300 mL
      of water between breakfast and the meal test, to guarantee normal hydration, not eating
      between breakfast and the meal test to guarantee a standard hunger level.

      Weight, height and blood pressure (BP) will be measured just before the test, systolic and
      diastolic blood pressure and heart rate will be measured 3 times and the participants will be
      requested to void just before being weighted and the urines produced thereafter during the 3
      h of the test will be collected.

      The meals will be consumed in groups of 4 volunteers at a time under standard conditions in
      the metabolic kitchen at Federico II University Hospital.

      The volunteers will be requested to drink 300 mL of water during the meal, which will have a
      maximum duration of 20 min. An additional volume of 300 mL has to be drunk in the 3 h after
      the meal. In both meals, at intervals of 30 min for a total of 3 h, a battery of Visual
      Analogue Scales (VAS) will be administered to assess possible differences in the satiating
      power of the two pizzas and their sensory characteristics, as described in the dedicated
      session.

      Blood samples will be drawn from an indwelling antecubital venous cannula for the measurement
      of glucose, insulin and sodium concentration in the fasting state and every 30 min thereafter
      for 3 h after eating was begun and the Area Under the Curve will be calculated.

      The volume of the 3 h urine collection will be measured, and the sodium and creatinine
      concentrations measured by ISE and by an enzymatic colorimetric method.
    

Intervention name(s): Seawater Pizza; Standard pizza
Intervention type(s): Other; Other
Intervention description(s): A seawater pizza administered to 12 healthy subjects; A standard pizza administered to 12 healthy subjects
Allocation: Randomized
Intervention model: Crossover Assignment
Intervention model description: Twelve healthy volunteers were recruited for a Randomized Controlled Trial, with the consumption of one Standard Pizza and one seawater pizza using a balanced crossover design, with 1 week wash out
Masking: Triple (Participant, Care Provider, Investigator)
Primary purpose: Prevention
Keywords: salt reduction; seawater; pizza; hedonic food; water and sodium handling