Soy Protein Isolate-Alginate Microspheres for Encapsulation ofEnterococcus faecalis HZNU P2

ABSTRACTIn this work, the mixture of alginate and soy protein isolate used as a wall material was developed to encapsulateEnterococcus faecalis HZNU P2 (E. faecalis HZNU P2). The survival ability in the simulated gastric fluid (SGF) and bile salt solution, storage stability at different temperatures and release properties in the simulated intestinal fluid (SIF) of encapsulated cells were assessed. The results showed that encapsulation could offer sufficient protection toE. faecalis HZNU P2. The viability of encapsulatedE. faecalis HZNU P2 did not decrease in SGF at pH 2.5 or 2.0 after 2 h incubation, while free cells were reduced from 11 to 9.85 log CFU/mL in SGF (pH 2.5) at the same exposure time. Only minor viability of encapsulatedE. faecalis HZNU P2 lost in 1.0 or 2.0% bile salt solution for 1 or 2 h exposure, compared with no survival of freeE. faecalis HZNU P2 under the same conditions. EncapsulatedE. faecalis HZNU P2 was completely released from the microspheres in SIF within 1 h. The viability of encapsulatedE. faecalisHZNU P2 stored for two weeks at 4°C was fully retained. Viabilities of encapsulatedE. faecalis HZNU P2, 9.6 and 9.0 Log CFU/g were obtained at 25 and 37°C after 21 days storage, respectively. However, around 1.0 log CFU/mL of free cells was reduced after two weeks storage at 4°C. EncapsulatedE. faecalis HZNU P2 using soy protein isolate and alginate as wall materials could play an important role in food applications.

Qualitative and quantitative assessment of genetically modified soy in enteral nutrition formulas by polymerase chain reaction based methods / Avaliação qualitativa e quantitativa de soja geneticamente modificada em fórmulas de nutrição enteral

OBJECTIVE: The aim of this work was to investigate the occurrence of Roundup Ready soybean in enteral nutrition formulas sold in Brazil. METHODS: A duplex Polymerase Chain Reaction based on the amplification of the lectin gene and the construction of the recombinant deoxyribonucleic acid of transgenic glyphosate-tolerant soybean (35S promoter and chloroplast transit peptide gene) was performed in order to analyze the deoxyribonucleic acid obtained from nine soy protein isolate-containing formulas. RESULTS: Despite the highly processed nature of the food matrices, amplifiable deoxyribonucleic acid templates were obtained from all tested samples, as judged by the amplification of the lectin gene sequence. However, amplicons relative to the presence of Roundup Ready soybean were restricted to one of the nine enteral nutrition formulas analyzed as well as to the soybean reference powder, as expected. Quantitative analysis of the genetically modified formula by real-time Polymerase Chain Reaction showed a content of approximately 0.3 percent (w/w) of recombinant deoxyribonucleic acid from the Roundup Ready soybean. CONCLUSION: The results show that one of the formulas contained genetically modified soy, pointing to the need of regulating the use of transgenic substances and of specific labeling in this product category.

OBJETIVO: Investigar a ocorrência de soja transgênica em fórmulas de suporte nutricional comercializadas no Brasil. MÉTODOS: Foi desenvolvido o método da reação em cadeia da polimerase duplex, com base na amplificação do gene na lectina, e na construção do ácido desoxirribonucléico recombinante da soja transgênica tolerante a glifosato (promotor 35S e gene de peptídeo de trânsito de cloroplasto), a fim de avaliar o ácido desoxirribonucléico extraído a partir das nove fórmulas contendo isolado protéico de soja. RESULTADOS: Apesar do alto grau de processamento aos quais os produtos avaliados foram submetidos, foi possível extrair ácido desoxirribonucléico amplificável a partir de todas as amostras, demonstrado pela amplificação do gene endógeno (lectina). Adicionalmente, o fragmento relativo à modificação genética da soja transgênica foi detectado em uma das nove amostras avaliadas, bem como na amostra relativa ao material de referência contendo 1,0 por cento de organismo geneticamente modificado. As análises quantitativas realizadas a partir da reação em cadeia da polimerase em tempo real revelaram a presença de aproximadamente 0,3 por cento de ácido desoxirribonucléico recombinante derivado de organismo geneticamente modificado na amostra de fórmula que apresentou resultado positivo. CONCLUSÃO: Os resultados demonstram que uma das fórmulas analisadas apresentava ingredientes derivados de soja geneticamente modificada, apontando para a necessidade de regulamentar a utilização de transgênicos, e de rotulagem específica nessa categoria de produtos.

STUDY ON ANGIOTENSIN CONVERTING ENZYME INHIBITORY PEPTIDES FROM DIGESTION OF SOY PROTEIN IN VITRO / 营养学报

Objective: To investigate if angiotensin converting enzyme inhilitory(ACEI) peptides would be produced from SPI digested by a batch digestion system using enzymes similar to digestive enzymes in humans.Method: Simulate the conditions of human gastrointestinal digestion in a model digestion system in vitro and produce soy peptides from SPI digested using pepsin and pancreatin.In addition to monitoring ACEI activity in the total soy protein digest,the possibility of generating soy peptide fractions with more potent activity than the unfractionated digest was investigated by measuring activity of fractions obtained after ultrafitration,anion exchange,and RP-HPLC.Results: The generation of ACEI activity in SPI was determined after sequential digestion with pepsin and pancreatin.The inhibitory activity was highest within the first 20 min at pepsin digestion and decreased upon subsequent digestion with pancreatin.An IC50 value of 0.28?0.06 mg/ml was determined after 180 min of digestion,while no ACEI activity was measured for the undigested SPI at 0.73 mg/ml.Chromatographic fractionation of the SPI digest resulted in IC50 values of active fractions ranging from 0.13?0.03 to 0.93?0.08 mg/ml.Conclusion: Many different peptides with ACEI activities were produced after pepsin-pancreatin digestion of SPI in vitro and lead to the speculation that physiological gastrointestinal digestion could also yield ACE inhibitory peptides from SPI.

A STUDY OF NUTRITION AND FOOD HYGIENE ON THE SOY PROTEIN CONCENTRATE AND SOY PROTEIN ISOLATE AS NEW DEVELOPED FOOD RESOURCE IN HEILONGJIANG PROVINCE IN CHINA / 营养学报

The nutritional and food hygienic character of the new developed soy protein concentrate and soy protein isolate in Heilongjiang province were studied by chemical analysis and rat experiment. These products have not yet been reported in China. The results indicated that the content of protein of soy protein concentrate and isolate was 69.76 and 83.11%(as anhydr-ate basic), the PER 2.00 and 1.34, the apparent digestibility 77.54 and 85.72%, the true digestibility 84.33 and 93.19%, the biological value 79.80 and 62.54%, the NPU 67.39 and 58.28% respectively.The essential amino acid composition of the two samples was the same as the products prepared in the other countries. By the hematological and pathological examination in rats, the contents of serveral harmful substan- ces were allowable or not detected. The authors belived that the nutritional quality of the two soy protein products was nearly the same as those in other countries, and its food safety was satisfactory.