scholarly journals INFLUENCE OF FACTORS ON THE BITTERNESS AND SENSORY TASTE IN PROTEIN HYDROLYSATE FROM SPENT

2018 ◽  
Vol 54 (4A) ◽  
pp. 172
Author(s):  
Nguyen Thi Thanh Ngoc

Spent brewer’s yeast, obtained after the main fermentation stage, is a rich- in-protein source (protein content accounts for 48 - 50 % dry matter). In order to use efficiently this protein source for using in food industry, it was hydrolysed by different methods into mixtures of peptides and amino acids. So that it has a wide range of applications in food. It can be used as emulsifying agents in a number of applications such as salad dressings, spreads, ice cream, coffee whitener, cracker, and meat products like sausages. However, bitterness in hydrolysates is one of the major undesirable aspects for various applications in food processing. In this study, influences of factors (E/S ratio, pH and temperature) on bitterness of hydrolysate were studied to choose the best hydrolysis conditions by using flavourzyme, alcalase and neutrase. The bitterness of hydrolysate was determined by intensity sensory method (using quinine standard) and amino acid content was analysed by HPLC method. The result showed that bitterness of brewer’s yeast hydrolysate by flavourzyme is the lowest and that by neutrase is the highest. In particular, the bitterness of hydrolysates have reached values of  15.2–40.42 µmol quinine/l (FH - flavourzyme hydrolysate), 21–64.99 µmol quinine/l (AH - alcalase hydrolysate) and 34.62–64.26 µmol quinine/l (NH - neutrase hydrolysate), respectively. The hydrolysis conditions in using flavourzyme were chosen at 50 oC, pH 7, E/S ratio 7.1U/g and in using alcalase - at 55 oC, pH 8, ratio E/S 7.2 U/g, respectively. At this conditions, bitterness reached values 15.44 µmol quinine/l (in FH) and 21.16 µmol quinine/l (in AH).

2018 ◽  
Vol 54 (2C) ◽  
pp. 458
Author(s):  
Nguyen Thi Thanh Ngoc

Brewer’s yeast spent, obtained after the main fermentation stage, is a rich- in-protein source(protein content accounts for 48 - 50 % dry matter). In order to use efficiently this source, it washydrolysed by different methods. Protein hydrolysate products are normally mixtures of peptidesand amino acids. Protein hydrolysates have a wide range of applications in food. It can be usedas emulsifying agents in a number of applications such as salad dressings, spreads, ice cream,coffee whitener, cracker, and meat products like sausages. However, bitterness in hydrolysates isone of the major undesirable aspects for various applications in food processing. In this study,we used enzymatic mixture alcalase and flavourzyme, yeast treatment methods to hydrolysebrewer’s yeast. The hydrolysate and fractions of protein hydrolysate obtained after filtration with10 kDa and 3 kDa filters were used for determination of bitterness and hydrophobic amino acidscontent. The bitter taste of hydrolysate was determined by sensory method (using quininestandard) and amino acid content was analysed by HPLC method. The result showed the closerelationship between bitter taste and hydrophobic amino acid content. The bitter taste of proteinhydrolysate was reduced as the hydrophobic amino acid content decreased. When the bitter taste(equivalent to quinine concentration) decreased from 16.25 μmol/l to 3.59 μmol/l, the totalcontent of hydrophobic amino acids in protein hydrolysate reduced from 1653 μg/ml to 932μg/ml.


2021 ◽  
pp. 110569
Author(s):  
Gabriela Vollet Marson ◽  
Débora Tamires Vitor Pereira ◽  
Mariana Teixeira da Costa Machado ◽  
Marco Di Luccio ◽  
Julian Martínez ◽  
...  

2018 ◽  
Vol 109 (2) ◽  
pp. 178-190 ◽  
Author(s):  
L. Goane ◽  
P.M. Pereyra ◽  
F. Castro ◽  
M.J. Ruiz ◽  
M.L. Juárez ◽  
...  

AbstractAnastrepha fraterculus (Wiedemann), a pest of great economic importance in South America, needs urgently to be controlled by environmentally friendly methods such as the sterile insect technique for which mass rearing of insects is required. Because oogenesis takes place during the adult stage, mass-rearing facilities should provide the females a diet that maximizes egg production at the lowest cost. Accordingly, we investigated the effect of artificial protein sources in the adult diet (yeast derivatives of different cost but with similar amino acids profiles, and the addition of wheat germ) on fecundity. Additionally, we evaluated different ratios of yeast derivatives or wheat germ on ovary maturation, fecundity, and fertility as well as their association with the nutrient content of females. Females fed hydrolyzed yeast and yeast extract attained the highest fecundity level, and those fed brewer's yeast the lowest. Reducing the amount of hydrolyzed yeast, an expensive protein source, in the diet negatively affected fecundity and ovary maturation. Increasing the amount of brewer's yeast, a low-cost protein source, did not favor fecundity. The addition of wheat germ in the adult diet improved fecundity regardless of the yeast derivate considered. Percentage of egg hatch was not affected by the diet. Nutrient content of A. fraterculus females varied according to the adult diet provided and mating status. Our findings provide novel baseline information to understand the role of nutrition on reproductive performance of A. fraterculus females and are discussed in the context of resource allocation. They also provide valuable advances in the search for cost-effective adult diets at fruit fly mass rearing facilities.


Author(s):  
Nominchuluu Ch ◽  
Enkh-Ariun A ◽  
Nomin B ◽  
Oyuntuya B ◽  
Bayarjargal M ◽  
...  

The aim of this study was to determine the effect of spent brewer's yeast hydrolysate on the stabilization of lecithincontaining oil-in-water emulsion. The emulsion was prepared using a 1: 9 oil-to-water ratio with 8% lecithin and homogenized for30 min at 10,000 and 13,000 rpm. The brewer's yeast hydrolysate was added to the lecithin-based oil-in-water emulsion by 0.5%, 1.5%, and 3%, respectively. The oil droplet diameter and creaming index of emulsions were determined by comparison with the control. The stability of the emulsion containing 1.5% of brewer's yeast hydrolysate was 88.2%, and the proportion of oil droplets with a diameter of 1.5-3 μm reached 80%, which is an advantage over other options. The addition of brewer's yeast hydrolysate to the emulsion by 1.5% resulted in a 4.4-fold increase in the IC50 value of 2,2ʹ -azinobis- (3-ethyl-benzothiazolin-6-sulfonic acid) (ABTS) cationic radical inhibition. These results suggest that the use of 1.5% brewer's yeast hydrolysate to produce lecithin-based oil-in-water emulsion has a positive effect on emulsion stability and antioxidant activity, while increasing nutritional value. Пивоны дрожжийн гидролизат агуулсан усан суурьтай эмульсийн тогтворжилтын судалгаа Хураангуй: Энэхүү судалгааны ажилд пивоны дрожжийн гидролизатыг лецитин агуулсан усан суурьтай эмульсийн тогтворжилтод үзүүлэх нөлөөллийг тодорхойлох зорилтыг тавьсан. Эмульсийг бэлтгэхэд тос, усны харьцааг 1:9,лецитинийг 8%-иар авч 10000 ба 13000 эрг/мин хурдтайгаар нийт 30 мин гомогенжүүлэв. Лецитин агуулсан усан суурьтай эмульсийн найрлагад пивоны дрожжийн гидролизатыг 0.5%, 1.5%, 3%-иар нэмж, эмульс дэх тосны бөмбөлгийн диаметр, өтгөрөлтийн индексийг хяналтын эмульстэй харьцуулан тодорхойлов. Пивоны дрожжийн гидролизатыг 1.5%-иар агуулсан эмульсийн тогтворжилт 88.2% байсан ба 1.5-3 μм диаметртэй бөмбөлгийн эзлэх хувь 80%-д хүрсэн нь бусад хувилбараас давуу үзүүлэлт болно. Пивоны дрожжийн гидролизатыг эмульсийн найрлагад 1.5%-иар нэмэхэд 2,2ʹ -azinobis-(3-ethylbenzothiazolin-6-sulfonic acid) (ABTS) катион радикал дарангуйлах IC50 утга 4.4 дахин нэмэгдэж байсан ба гидролизатын концентрацаас хамааран эмульсийн антиоксидант идэвх нэмэгдэж байсан. Эдгээр дүн лецитин агуулсан усан суурьтай эмульс гарган авахад пивоны дрожжийн гидролизатыг 1.5%-иар нэмж ашиглах нь тэжээллэг чанарыг нэмэгдүүлэхийн хамтаар эмульсийн тогтворжилт, антиоксидант идэвхэд эерэгээр нөлөөлж байгааг харуулж байна.  Түлхүүр үг: Гидролизат, эмульс, бөмбөлгийн хэмжээ, тогтворжилт, антиоксидант идэвх


2011 ◽  
Vol 76 (2) ◽  
pp. C272-C278 ◽  
Author(s):  
Eun Young Jung ◽  
Hyun-Sun Lee ◽  
Jang Won Choi ◽  
Kyung Soo Ra ◽  
Mi-Ryung Kim ◽  
...  

2019 ◽  
Vol 19 (S1) ◽  
Author(s):  
Georgios A. Kyritsis ◽  
Antonios A. Augustinos ◽  
Spyridon Ntougias ◽  
Nikos T. Papadopoulos ◽  
Kostas Bourtzis ◽  
...  

Abstract Background Insect species have established sophisticated symbiotic associations with diverse groups of microorganisms including bacteria which have been shown to affect several aspects of their biology, physiology, ecology and evolution. In addition, recent studies have shown that insect symbionts, including those localized in the gastrointestinal tract, can be exploited for the enhancement of sterile insect technique (SIT) applications against major insect pests such as the Mediterranean fruit fly (medfly) Ceratitis capitata. We previously showed that Enterobacter sp. AA26 can be used as probiotic supplement in medfly larval diet improving the productivity and accelerating the development of the VIENNA 8 genetic sexing strain (GSS), which is currently used in large scale operational SIT programs worldwide. Results Enterobacter sp. AA26 was an adequate nutritional source for C. capitata larvae, comprising an effective substitute for brewer’s yeast. Incorporating inactive bacterial cells in the larval diet conferred a number of substantial beneficial effects on medfly biology. The consumption of bacteria-based diet (either as full or partial yeast replacement) resulted in decreased immature stages mortality, accelerated immature development, increased pupal weight, and elongated the survival under stress conditions. Moreover, neither the partial nor the complete replacement of yeast with Enterobacter sp. AA26 had significant impact on adult sex ratio, females’ fecundity, adults’ flight ability and males’ mating competitiveness. The absence of both yeast and Enterobacter sp. AA26 (deprivation of protein source and possible other important nutrients) from the larval diet detrimentally affected the larval development, survival and elongated the immature developmental duration. Conclusions Enterobacter sp. AA26 dry biomass can fully replace the brewer’s yeast as a protein source in medfly larval diet without any effect on the productivity and the biological quality of reared medfly of VIENNA 8 GSS as assessed by the FAO/IAEA/USDA standard quality control tests. We discuss this finding in the context of mass-rearing and SIT applications.


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