Content uploaded by M.J. Robert Nout
Author content
All content in this area was uploaded by M.J. Robert Nout on Feb 11, 2015
Content may be subject to copyright.
Tempeh as a Functional Food
... shows how E. coli cells adhere to intestinal brush border vesicles (inset) , and how certain extracts made of mould fermented soybean strongly reduce the adherence of the pathogen to its receptors in the brush border. This reduced adherence and other beneficial effects such as restoratrion of fluid balance lead to better feed conversion and growth (Nout and Kiers, 2004). ...
Foods that have nutritional value along with additional health advantages are referred to as functional foods. Fruits, vegetables, and spices are rich sources of antioxidants, which can help prevent damage from free radicals and environmental stress. It has been demonstrated that consuming foods high in antioxidants lowers the risk of degenerative diseases such as cancer, emphysema, immunological deficiencies, respiratory disorders, heart disease, and stroke. It also lowers the risk of Parkinson’s disease and other inflammatory conditions. Traditional Indonesian fermented soybean-based food products, or soybeans and known as “tempe”, have been associated with a host of health benefits, including a lower risk of cardiovascular disease, a lower risk of cancer, improved bone health, and enhanced immunological function. This article investigates tempe’s potential as a meal with antioxidant properties and suggests a mechanism via which it can trigger the Nrf2-mediated antioxidant response. The study offers insights into the potential applications, development, and potentiation of tempe by synthesizing potential biomolecular pathways for its antioxidant actions at the cellular level.
A randomized controlled double-blind clinical trial was conducted to evaluate tempe-based formulated foods for
treatment of young Indonesian children suffering from acute diarrhea. A total of 214 cases aged between 6 and 24 months
visiting two teaching hospitals, i.e., Sardjito hospital (n=102) in Yogyakarta and Karyadi hospital (n=112) in Semarang. Two
cases from one hospital were dropped because they moved to other towns. In addition to their hospital food given during
hospitalization and daily food at home, 72 cases were given tempe-based formulated foods with tempe produced traditionally
(group TT), 72 were given tempe produced industrially (group IT), whereas a control group of 68 received soybean powder
formulated foods (group IS). Formula feedings were started immediately following WHO (world health organization) standard
oral rehydration therapy (ORT) and continued at the patients homes for up to 90 consecutive days, including feedings during
hospitalization. Follow-up observations at patients homes were conducted twice weekly. The initial clinical characteristics of
the cases in each group were similar. Using analysis of variance there was a non significant trend towards a shorter duration
of diarrhea in the groups using tempe based formula (p=0.079). Using the t-test, the duration of diarrhea appeared to be
significantly shorter only for the group using formula with traditional tempe compared with the group using soy formula
(p=0.035). The total amount of feeding formula and the total amount of calories consumed at the hospital and at home was
similar for all three groups, although the group receiving the control formula consumed a somewhat higher amount of breast
milk (p=0.045) and a lower amount of solid food at home. Weight for age was below normal at the start of the study or after
rehydration (Z-score between -1.0 and -1.4) and approached the normal value at the end of the study for all three groups (Zscore
between -0.51 and -0.27). The increase in Z-score was highest in the groups receiving tempe based formula (+1.0 in
the TT group and +0.9 in the IT group) and lowest in the IS group (+0.7). This implies that a tempe based formula can diminish
the duration of acute diarrhea and improve weight gain following an episode of acute diarrhea.
During tempeh fermentation, Rhizopus oligosporus produced polysaccharidases to degrade soya bean cell walls; the maximum activity for all polysaccharidases tested occurred 20–30 h after inoculation. R. oligosporus was also grown in a soya bean extract model medium to which glycerol was added to control water activity (a
w). The overall activities of the major enzymes produced by the fungus, polygalacturonase, endocellulase and xylanase, appeared to be strongly influenced by a
w. The production of enzymes as well as their specific activities were affected by a
w. The optimum a
w for polygalacturonase and xylanase activity coincided with that for mycelial growth, namely 0.99–1.00. In contrast, the optimum a
w for (endo)cellulase was 0.98, at which mycelial growth was significantly reduced.
In the present study we isolated and identified two mixtures of fatty acid esters of β-sitosterol glucoside from soybeans and its fermented product, tempe. The mixtures of glucolipids occurring in soybeans and tempe are unseparable and possess the following structures: sitosterol-3-O-β-D-(6'-O-palmitoyl/-linoleoyl)- and sitosterol-3-O-β-D(6'-O-palmitoyl/-stearoyl)-glucopyranoside, respectively. Since tempe constituents show antitumor activity, we tested these glucolipids against mouse myeloma cells (tumor cells). The tempe glucolipid mixture showed higher inhibition (95.3%) at the 50 μg/ml concentration than the soybean one. The maximum activity of the soybean glucolipid mixture was (96%) at 100 μg/ml.
The proteolytic capacity of 36 strains of the genus Rhizopus isolated from Indonesian tempe or tempe inocula was examined. No significant changes in the total amount or pattern of amino acids could be found, but there was a distinct increase in the amount of free amino acids. Strains with a high proteolytic activity were found, which were able to release nearly five times more amino acids after standard fermentation than others. Changes in fermentation parameters such as temperature or relative humidity improved these results. Fermentations with mixed populations of bacteria and Rhizopus yielded a lower level of free amino acids, but an increased total amount of amino acids. Examination of protease systems of three Rhizopus species showed that the proteases of the cell wall fraction were most responsible for proteolytic capacity of the different strains. On average their activity amounted to 71% of the total proteolytic capacity.
Common beans are an important source of energy and nutrients, but have significant amounts of antinutritional factors and a limited digestibility. A nutritious weaning food was developed by combining fermented black beans and rice. Raw beans were coarsely ground, soaked, cooked, fermented with Rhizopus oligosporus for 15, 20, or 25 h, and then homogenized to obtain a supernatant and a precipitate. Raw, cooked, and fermented beans, and the precipitates were chemically characterized and the data statistically analyzed to choose an optimum fermentation time to develop the weaning food product. Ash and mineral contents of the beans decreased after soaking and in the precipitates. Cooking improved protein digestibility and decreased the levels of lectin and trypsin inhibitor. The oligosaccharide content of beans fermented 25 h was lower than in the other treatments. The weaning food product (27% 25 h fermented beans, dry weight/73% cooked rice, dry weight) had an in vitro protein digestibility of 86% and a very low content of oligosaccharides. Keywords: Dry beans; Phaseolus vulgaris; fermentation; tempeh-like products; weaning foods
The effects of processing techniques on the distribution of isoflavones were investigated by manufacturing tempeh, soymilk, tofu, and protein isolate. The manufacturing steps causing significant losses (p < 0.05) of isoflavones were as follows: soaking (12%) and heat processing (49%) in tempeh production; coagulation (44%) in tofu processing; and alkaline extraction (53%) in soy protein isolate production. In the production of tempeh, soymilk, and tofu, malonyldaidzin and malonylgenistin decreased after soaking and cooking. Concomitantly, acetyldaidzin and acetylgenistin were generated during heat processing. After fermentation, daidzein and genistein concentrations increased in tempeh, apparently as a result of fungal enzymatic hydrolysis. In protein isolate processing, alkaline extraction caused the generation of daidzein and genistein, probably through alkaline hydrolysis. Keywords: Isoflavones; mass balance; soy protein isolate; tempeh; soymilk; tofu
Dried tempeh is known to be significantly stable to lipid oxidation compared with unfermented soybeans (BS). A new antioxidant was isolated from the methanol extract of tempeh and identified as 3-hydroxyanthranilic acid (HAA) by UV, IR, EI-MS, and 1H-, 13C-, HMQC-, and HMBC-NMR techniques. HAA was effective in preventing autoxidation of soybean oil and soybean powder, while 6,7,4‘-trihydroxyisoflavone (a well-known antioxidant) was not. HAA also exhibited strong antioxidative activity in both water/ethanol and rabbit erythrocyte membrane ghost systems. HAA was not found in BS, but was produced during the incubations with Rhizopus oligosporus IFO 32002 and 32003. The amount of HAA reached a maximum at the stage of 2 days (acceptable), which had the strongest antioxidative activity. Keywords: Tempeh; fermented soybean product; antioxidant; 3-hydroxyanthranilic acid
Amounts of dry matter, ash, protein, free ammonia, crude lipid, glyceride–glycerol, free fatty acids, free glycerol, glucosamine, protease activity and lipase activity were monitored during the fermentation of bacteria-free tempe made with acidified soya bean cotyledons and Rhizopusoligosporus NRRL 2710 at 30°C. During the phase of mycelial growth (0–32 h) the total dry matter decreased by approximately 10% (w/w), accounted for by losses of crude lipid (3% of initial dry matter), protein/amino acids (0·5%), and unidentified compounds (6·5%). During the phase of mycelial senescence (60–180 h), decrease in dry matter (12% of initial dry matter) was due almost entirely to loss of crude lipid. Lipase activity and the production of free fatty acids occurred from the earliest stages of the fermentation. The production of only small amounts of free glycerol indicates that triglycerides were primarily hydrolysed to partial glycerides and free fatty acids. Protease activity and production of free ammonia were also detected at the earliest stages of the fermentation. During the phase of mycelial senescence, amounts of crude lipid and glycerol decreased in the absence of fungal growth, possibly due to the activity of enzymes released from senescent mycelium.
Aims: To evaluate anti-diarrhoeal and growth enhancing properties of fermented soya beans in weaned piglets.
Methods and Results: In a first phase piglet diet, toasted full-fat soya beans (20%) were replaced with either cooked soya beans or Rhizopus microsporus or Bacillus subtilis fermented soya beans. The effect on the incidence, severity and duration of diarrhoea in enterotoxigenic Escherichia coli (ETEC)-challenged weaned piglets was determined (pen trial, 24 piglets per treatment). Severity of diarrhoea was significantly less on the diet with Rhizopus-fermented soya beans compared with the control diet containing toasted soya beans. Piglets fed fermented soya beans showed increased feed intake (13 and 12%), average daily weight gain (18 and 21%) and feed efficiency (3 and 8%) (for Rhizopus and Bacillus-fermented soya beans, respectively). However, in the treatment groups an unequal mortality and a potential unequal distribution of receptor-positive piglets were observed.
Conclusions: Cooked and fermented soya beans could be beneficial in the control of diarrhoea in ETEC-challenged weaned piglets (particularly Rhizopus fermented) and significantly improved weight gain and feed intake (particularly Bacillus fermented).
Significance and Impact of the Study: Fermented soya beans could offer benefits with respect to the control of diarrhoea and feed efficiency in piglets.
Tropical legumes, ie soya bean and cowpea, were pre-treated and subsequently fermented using pure cultures of Rhizopus spp. Impact of soaking, cooking and fermentation of the legumes on their digestibility was determined using an in vitro digestion method. Processing of white maize included, amongst others, natural lactic acid fermentation, cooking and saccharification using barley malt. An in vitro method was standardised to carry out comparative determinations of the dry matter digestibility of cereal and legume food samples as a function of processing conditions, without attempting to exactly mimic gastrointestinal digestion. Using this method based on upper digestive tract digestion, it was observed that digestibility of the legumes increased during cooking and fermentation. Cooking improved the total digestibility of both soya bean and cowpea from 36.5 to 44.8% and from 15.4 to 40.9% respectively. Subsequent fungal fermentation increased total digestibility only by about 3% for both soya bean and cowpea. Digestibility was also influenced by fungal strain and fermentation time. Cooking and subsequent saccharification using malt almost tripled total digestibility of white maize from 25.5 to 63.6%, whereas lactic fermentation of maize had no effect on in vitro dry matter digestibility. Although total digestibility of cooked legumes was only slightly improved by mould fermentation (3% for both soya bean and cowpea), the level of water-soluble dry matter of food samples increased during fermentation with Rhizopus oryzae from 7.0 up to 27.3% for soya bean and from 4.3 up to 24.1% for cowpea. These fermented products could therefore play a role as sources of easily available nutrients for individuals suffering from digestive disorders.© 2000 Society of Chemical Industry