Gas chromatography-mass spectrometry-based metabolite profiling and sensory profile of Indonesian fermented food (tempe) from various legumes.

Tempe is an Indonesian fermented food prepared from soybean or other non-soy legumes. Non-soy legumes based tempes have been reported to have a nutritional profile different from that of soybean-based tempe. However, a comprehensive study of the metabolite and sensory profiles of legume tempes has not been conducted. This study investigated the metabolite profile of legumes before and after fermentation using a metabolomic approach and its relation to the sensory profile. Four different legumes, namely red kidney bean, soybean, cowpea bean, and jack bean, and four kinds of tempe prepared from the abovementioned legumes were subjected to gas chromatography-mass spectrometry (GC-MS) analysis. These tempe samples were fermented in two different production places, Japan and Indonesia. In total, 83 metabolites were annotated from all samples. Principal component analysis (PCA) showed that the samples were separated based on their type (legume and tempe) along PC1 with a 36.3% variance, in which sugars and amino acids significantly contributed to the separation. In addition, samples were separated along PC2 with a 17.2% variance based on the different production places. The combination of 75% soybean and 25% red kidney bean (75S:25R) could increase the concentrations of amino acids that were initially low in soybean tempe. The 75S:25R tempe showed no significant differences in taste and texture preference compared to the 100% soybean tempe, based on sensory result. These findings provide evidence that metabolomics could be used to identify the differences between tempes from different legumes.

The role of soy plant-based formula supplemented with dietary fiber to support children's growth and development: An expert opinion.

OBJECTIVES: Soy-based formula has evolved in usage and processing technology since its introduction in 1909, and has been used as substitute formula for infants or children with cow milk allergy since 1929. At present, personal opinions, religious background, availability, palatability, and cost are part of the reasons soy-based formula is chosen. Technology in processing soy-based formula has evolved from using soy flour to soy protein isolate, which provides advantages. However, concerns remain regarding the impact of its use on the growth and development of children. METHODS: An expert meeting, attended by 12 experts, was initiated in Jakarta, Indonesia, to obtain an evidence-based consensus on the role of soy protein isolate formula, as well as its nutritional value to support growth and development. RESULTS: Ensuring that plant-based formula (i.e., soy protein isolate formula) is fortified with key nutrients, such as calcium, iron, and dietary fiber is important. CONCLUSIONS: Consensus was achieved, concluding that soy protein isolate formula is safe, affordable, and an alternative option for cow's milk-based formula for term infants.

Metabolomics-Based Study of the Effect of Raw Materials to the End Product of Tempe-An Indonesian Fermented Soybean.

Tempe is a fermented soybean food from Indonesia, made by inoculating Rhizopus spp. onto cooked and dehulled soybean. Tempe has been a part of Indonesian culture since the 16th century and is now produced globally as a highly nutritious plant-based food. Despite a longstanding history on the production of tempe, very few studies have been reported to understand the effect of raw material to the end product metabolite composition. In this research, we applied GC/MS-based metabolite profiling to investigate the effect of various possible factors that might affect the final product (environmental factors, raw materials, and starter cultures). Representative samples were tempe produced by Indonesian industries, Japanese industries as well as laboratory made tempe. The results showed that both environmental factors and raw materials (soybean, water, and starter culture) contributed to the tempe metabolite profile. Here we found the possibility that starter cultures might play a greater role to determine the metabolite profiles compared to other tested factors. This research might provide useful insights for the larger scale industries to maintain the quality of tempe for the benefit of the consumers.

The Physicochemical Properties of Tempe Protein Isolated from Germinated and Non-Germinated Soybeans.

Tempe is an indigenous Indonesian source of protein. In this study, the tempe was produced from Grobogan soybeans with two types of treatment, germinated and non- germinated. The two types of tempe produced were then processed into protein isolates, tempe protein isolate from non-germinated soybeans (NGTI) and tempe protein isolate from germinated soybeans (GTI). This study was aimed to compare the physicochemical properties of NGTI, GTI, and CSI (commercial soy protein isolate). Seen from the physical characteristics, the NGTI and GTI were superior to CSI in their bulk density which was very significantly higher (p<0.01) at 0.54, 0.57 and 0.39 g/mL, respectively, and the aw value which was very significantly lower (p<0.01) at 0.05, 0.04 and 0.34, respectively. As for the chemical characteristics, the NGTI and GTI were superior to CSI in their protein content which was very significantly higher (p<0.01) at 79.16, 82.89 and 74.90%, respectively, the in vitro protein digestibility which was also significantly higher (p<0.05) at 76.95, 77.82 and 76.68%, respectively, and the fat content which was very significantly lower (p<0.01) at 1.45, 1.28, and 2.74%, respectively.

Equivalence Test between the Physicochemical Properties of Transgenic and Non-Transgenic Soy Flour.

Soybeans are a source of plant-based protein with a fairly complete composition of essential amino acids. Most of the soybean raw material in Indonesia originates from the United States of America where around 75% of the soybeans are transgenic soybeans (Roundup Ready GMO). One of the easily produced and practical soybean products is soy flour. The purpose of this study was to compare the physicochemical properties of flour made from three types of soybeans: local soybeans, imported transgenic soybeans, and imported non-transgenic soybeans. The study was conducted in two phases: the preliminary study, where the physicochemical properties of the three varieties of soybeans were assessed, and the main study which involved the production of soy flour and the analysis of their physicochemical properties. The results of the preliminary analysis revealed that the local soybeans had greater length and width dimensions, volume, bulk density, 100-seed weight, and protein content than transgenic and imported non-transgenic soybeans. The statistical analysis demonstrated that soybean variety had a significant effect on the physicochemical properties of the flour produced, namely the yield, color, water activity, bulk density, repose angle, moisture, ash, protein, fat, and mineral content, and the antioxidant capacity parameters. On the other hand, soybean variety did not have a significant effect on the carbohydrate and total phenolic content. Based on the physicochemical properties, local soy flour had a number of properties that were equivalent to those of imported soy flour and was even superior in its protein content and antioxidant capacity.

Calcium Bioavailability of Tempe and Boiled Soybean Flours and Its Effect on Osfemurs in Experimental Rats.

Tempe is a nutritious food that contains both macronutrients and micronutrients in an adequate amount. Tempe contains a high amount of calcium, so it is an affordable food product that can be purchased by most people in Indonesia. Calcium deficiency can lead to several diseases and disorders such as osteoporosis, hypertension, heart disease, and nerve damage. This study was aimed to evaluate: (1) the calcium bioavailability (absorption and retention) of tempe and boiled soybean flours compared to casein (control), (2) the effect of tempe and boiled soybean flours on blood calcium and osfemurs in rats. This study was conducted using rats as a model. The rats were divided into four treatment groups based on the sources and protein concentrations in the diet; tempe flour 10% protein, tempe flour 20% protein, boiled soybean flour 10% protein, and casein 10% protein as a control. This experiment was conducted for over than 90 d. The results showed that the sources of protein (casein, tempe flour, and boiled soybean flour) and protein level in the diet (10% and 20%) had no significantl effect (p>0.05) to the calcium absorption, calcium retention, calcium content in serum, calcium content in osfemurs, and total calcium in osfemurs. Tempe flour and boiled soybean flour can be consumed as a calcium source to substitute the consumption of calcium from dairy products.

Gas chromatography coupled with mass spectrometry-based metabolomics for the classification of tempe from different regions and production processes in Indonesia.

Tempe, a fermented soybean originally from Indonesia, is an excellent protein source with high nutritional quality. Differences in the production process and unique fermentation condition in different regions result in varieties of tempe. Despite its high cultural and economic values, there are very few studies on the characterization of tempe based on the differences of production process and geographical origin. Metabolomics is a powerful tool assessing food quality, food safety, and determination of origin and varietal differences. In this study, metabolomics is applied for the study of Indonesian tempe obtained from various regions and different production processes. Seventeen samples were collected from 6 different cities in Java Island, which were produced by local tempe crafters (traditional), semi-modern industry and modern industry. Untargeted metabolomics by gas chromatography coupled with mass spectrometry (GC/MS) was implemented to discriminate various kinds of tempe and identify metabolites that are associated with these differences. Results showed that tempe produced in different places clustered together according to the cities and their production category. Sugars and amino acids groups were found to be primary compounds that contributed to this result. This is the first report that address the metabolic differences between different varieties of tempe from different regions and production processes. The knowledge from this study is important for future development of tempe production.