Vanillin is a flavor widely used in the food industry. This paper discusses the application of vanillin in the food industry, worldwide limits for the use of vanillin, the characteristics of the production technology and the possible risks brought by vanillin for foods, and it also summarizes the methods for vanillin detection in dairy products, infant formulas and formulas for special medical purposes intended for infants including gas chromatography (GC), liquid chromatography (LC), gas chromatography-tandem mass spectrometry (GC-MS/MS), liquid chromatography-tandem mass spectrometry (LC-MS/MS), and spectroscopy with special attention to their advantages and limitations. This review is expected to provide a basis for the detection and further research of vanillin in infant formulas for special medical purpose.

Hydrolyzed protein formula not only solves the problem of allergy or intolerance to cow’s milk proteins in infants and young children, but also meets the nutritional needs. Degree of hydrolysis is an important parameter to evaluate hydrolyzed protein formula. However, there are currently no methods available to determine the degree of hydrolysis of hydrolyzed protein formula. This article presents a brief introduction to the basic concepts of hydrolyzed protein formula and its degree of hydrolysis, and summarizes the existing methods for detecting the degree of hydrolysis of proteins. We expect this review to provide a reference for the establishment of detection methods for the degree of proteolysis of hydrolyzed protein formula.

Ion chromatography was used to determine the inositol content in formula foods for special medical purposes. The sample was acidified by hydrochloric acid to precipitate proteins, and inositol was dissolved in the supernatant and then detected with an amperometric detector. The results showed that the peak area was linearly related to the concentration of inositol in the range of 0.025 to 40.000 mg/L with a correlation coefficient (R2) of 0.999 9. The detection limit and quantitation limit were 0.125 and 0.5 mg/100 g, respectively. The average recovery of inositol was 83.1%–102.9% at different spiked levels. The method was proved to be simple, sensitive reproducible and suitable for the determination of inositol in formula foods for special medical purposes.

In this study, the applicability of hydride generation atomic fluorescence spectrometry (HG-AFS) and inductively coupled plasma mass spectrometry (ICP-MS), methods I and III specified in the national standard GB 5009.93—2017, respectively to detect selenium in infant formula for special medical purposes was researched. Seven laboratories separately determined the selenium content in six samples of 3 types of infant formula for special medical purposes and infant formula quality control samples, and measured the recoveries. The results showed both methods were suitable for the determination of selenium in infant formula, while the applicability for various types of infant formula foods for special medical purposes needs to be further studied.

In order to establish an efficient method for the determination of L-carnitine in infant formula for special medical purposes, the spectrophotometric method for the determination of L-carnitine in foods for infants and young children and dairy products specified in the national standard GB 29989—2013 was optimized with respect to standard curve preparation, sample pretreatment and enzyme preparation. The results showed that under the following conditions: using the optimized standard curve, enzyme extraction at a rotation speed of no less than 6 000 r/min, and hydrolysis of 5 g of homogeneous milk powder (accurate to 0.000 1 g) with 0.25 g of α-amylase at 50 ℃ for 30 min, the optimized method exhibited high precision and spiked recovery. This method could overcome the problems encountered in the determination of L-carnitine in infant formula for special medical purposes by the traditional method such as cloudy filtrate, the dark color of prepared samples that could interfere with the determination of absorbance and low spiked recovery, being suitable for the large-scale determination of L-carnitine in amino acid-based infant formula, extensively hydrolyzed protein infant formula and partially hydrolyzed protein infant formula for special medical purposes.

The applicability of silver nitrate titration and potentiometric titration, two of the three detection methods for chlorine in food samples specified in the national standard GB 5009.44—2016, for infant formula for special medical purposes was evaluated. The results showed that the spiked recoveries of silver nitrate titration for partially hydrolyzed protein infant formula, extensively hydrolyzed protein infant formula, and amino acid-based infant formula for special medical purposes were 95%–108%, 98%–125% and 100%–106%, respectively, and the relative standard deviations (RSD) for precision were between 12.7% and 32.9%. The results of potentiometric titration was lower than that of silver nitrate titration.

This research investigated the effects of reconstitution pH value and temperature, storage duration, sunlight exposure and reheating on the contents of vitamin B1 and vitamin D in six different kinds of formula foods for special medical purposes sold on the market. The results showed that the vitamin B1 content decreased with increasing reconstitution pH value and temperature and storage time, but was little affected by reheating. The vitamin D content decreased with storage time in sunlight. pH value and reheating had little effect on the content of vitamin D. The optimum conditions for ensuring the highest utilization ratio of vitamin B1 and vitamin D in formula foods for special medical purposes were reconstitution in acidic water (pH < 7) at 40–60 ℃, storage in darkness and preferably use immediately after reconstitution.

As a nutritional supplement for people with special needs, the food for special medical purposes (FSMP) has occupied an important position in the global market. As the main source of added nutritional components in FSMP, nutritional fortifiers are of great significance to improve its quality. This paper focuses on the comparative analysis of the standards and regulations of the Codex Alimentarius Commission (CAC), the EU and China on nutrients and nutritional fortifiers in FSMP with respect to limits, ingredients, sources, and so forth, in order to provide useful information for improving the standards for the use of nutritional fortifiers in FSMP in China.