The impact of immersion time in lime solution on antioxidant and antidiabetic properties and consumer evaluation of Sargassum hystrix seaweed tea

Damayanti Rahmatika Pratiwi, Amir Husni

Abstract. Sargassum hystrix is a brown seaweed that contains bioactive substances, such as antioxidant
and antidiabetic compounds, and is used as a functional ingredient in the food industry. They are mostly
found in Indonesian waters, growing along rocky shorelines. Since the beverages extracted from seaweed
are found to be less preferred by consumers due to the fishy smell, efforts are needed to curtail this problem. Based on this condition, the lime solution immersion method is observed as a suitable approach to reduce the pungent smell. Therefore, this study aims to determine the effect of the immersion time of the lime solution on antioxidant and antidiabetic properties, as well as on consumers’ preference for S. hystrix tea. In this research, the variation of seaweed immersion time at 0, 4, 8, 12, and 16 min, was used in a lime solution of pH 5 at 85°C. Multiple analyses were further carried out on the beverage, including moisture and total phenol content, hedonic teat, and antioxidant property, such as inhibitions of DPPH (1,1-diphenyl-2-picrylhydrazyl), FRAP (ferric reduction antioxidant power), and α-glucosidase. The results indicated that the immersion time had no effect (p > 0.05) on the water content, although it significantly affected total phenol levels, antioxidant, and antidiabetic activities, as well as the consumer preference for S. hystrix tea (p < 0.05). The best quality was obtained at 16 min, which indicated water and total phenol contents at 3.10 ± 0.33% and 76.81±0.23 mg GAE g-1, with DPPH, FRAP, and α-glucosidase inhibitionactivities at 53.86±1.27%, 121.82±0.91 µM g-1 , and 52.86±0.89%, respectively. It also showed consumer evaluations for appearance, color, flavor, taste, and overall quality, at 4.39±0.91, 4.33±0.78, 4.08±1.23, 4.25±1.08, and 4.26+0.13, respectively. Furthermore, immersion time in lime solution improved the quality and consumer evaluation of S. hystrix tea.
Key Words: Bioactive, brown seaweed, consumer preference, fishy smell, functional food. read more

Mohamad Aji Ikhrami1, Jaka Widada2, Indun Dewi Puspita1 and Masagus Muhammad
Prima Putra1*

1Fish Product Technology, Department of Fisheries, Faculty of Agriculture, Universitas Gadjah
Mada, Jl. Flora gedung A4, Bulaksumur Yogyakarta 55281
2Department of Agricultural Microbiology, Faculty of Agriculture, Universitas Gadjah Mada, Jl.
Flora gedung A4, Bulaksumur Yogyakarta 55281
*Corresponding author, e-mail: primaputra@ugm.ac.id

ABSTRACT
Streptomyces is a Gram-positive bacteria that produces the largest secondary metabolite
compounds. The results of whole-genome sequence analysis showed that Streptomyces can carry
more than 30 Biosynthetic Gene Clusters (BGC) encoding secondary metabolites that have the
potential to be explored in the exploration for new bioactive compounds. However, not all BGC
can be expressed in the laboratory scale and requires a specific activation method. This study aims
to explore the potential of chitosan as an elicitor compound to activate and or increase the
antibacterial activity of Streptomyces sp. GMR-22 was tested against histamine-producing bacteria
(HPB) Morganella morganii TK7 and Citrobacter freundii CK1. Chitosan was added to the
fermentation medium with the final concentration of 250, 500, and 750 μg/ml while without the
addition of chitosan used as control. Fermentation was carried out for 10 days at room temperature,
with constant agitation 200 rpm. The supernatant was separated by centrifugation at 3500 rpm for
15 minutes, then fractionation with ethyl acetate, concentrated by vacuum rotary evaporator, and
freeze-dried. The test for antibacterial activity was carried out by the microdilution method with
an extract concentration of 100 mg/ml. The test results of the microdilution method showed that
the addition of chitosan successfully increases the antibacterial activity with the highest activity
shown by the water fraction of 250 μg/ml addition of chitosan which is effective in inhibiting the
growth of Morganella morganii TK7 and Citrobacter freundii CK1 by 97,29% and 97,92%
respectively. read more

Pris Larasati1, Amir Husni2*
1Departemen Perikanan Fakultas Pertanian Universitas Gadjah Mada
2Pusat Kajian Ketahanan dan Keberlanjutan Hasil Laut Departemen Perikanan Fakultas Pertanian
Universitas Gadjah Mada

Abstrak
Rumput laut Sargassum crassifolium mempunyai bioaktivitas yang tinggi sehingga berpotensi sebagai
sumber pangan fungsional, salah satunya dibuat menjadi teh rumput laut. Salah satu kelemahan teh rumput laut yaitu kurang disukai konsumen karena adanya bau amis. Penelitian ini bertujuan untuk mengetahui pengaruh lama perendaman dalam air 85oC terhadap karakteristik dan tingkat penerimaan konsumen teh rumput laut S. crassifolium. Rancangan acak lengkap digunakan dalam penelitian ini, dengan perlakuan berupa variasi lama waktu perendaman. Teh rumput laut dibuat dengan cara merendam dalam air ±85oC selama 0, 4, 8, 12, dan 16 menit kemudian dipotong-potong lalu disangrai. Teh rumput laut S. crassifolium dianalisis meliputi: kadar air, total fenol, aktivitas antioksidan dengan metode 2,2-diphenyl-1-picrylhydrazyl (DPPH) dan Ferric Reducing Antioxidant Power (FRAP), aktivitas penghambatan α-glukosidase dan uji hedonik. Hasil penelitian menunjukkan bahwa lama perendaman berpengaruh nyata (p<0,05) terhadap kadar air, total fenol, aktivitas antioksidan, penghambatan α-glukosidase, dan tingkat penerimaan konsumen. Perlakuan terbaik yaitu lama perendaman 16 menit dengan kadar air 3,35±0,41%, total fenol 68,63±0,67 mg GAE/g, aktivitas penghambatan DPPH 55,99±1,01%, nilai FRAP 116,97±1,89 μM/g, penghambatan α-glukosidase 55,67±0,36%, dan nilai hedonik parameter aroma, rasa, warna, kenampakan, dan keseluruhan secara berturut-turut yaitu 4,29±1,18; 4,59±0,85; 4,18±0,98; 4,43±0,91; 4,37±0,98. read more

Fatma Nadya Nursyamsi, Amir Husni*
Department of Fisheries Faculty of Agricultur e Universitas Gadjah Mada, Yogyakarta, Indonesia

Abstract:
The brown seaweed Sargassum polycystum contains bioactive compounds, including antioxidants
and antidiabetes, letting it be a functional food ingredient such as seaweed tea. However, seaweed tea is less preferred by consumers because of its fishy smell, which must be reduced using various methods, including soaking in a lime solution. This study aims to determine the effect of the soaking time in lime solution on the antioxidant activity, antidiabetic activity, and consumer acceptance of S. polycystum seaweed tea. In this study, the seaweed was soaked in a lime solution at pH 5 at 85°C for 0, 4, 8, 12, and 16 minutes. Analysis was conducted on S. polycystum seaweed tea to obtain the moisture content, total phenol, antioxidant activity (inhibition of 1,1 diphenyl 2 picrylhydrazyl (DPPH), and ferric reduction antioxidant power (FRAP)), the inhibitory activity of α glucosidase, and consumer preference test using hedonic. The results show that the soaking time in the lime solution at pH 5 had no effect on the water content but had a significant effect (p<0.05) on the total phenol, antioxidant and antidiabetic activities and consumer preference of S. polycystum seaweed tea. The best treatment was obtained a t 16 minutes of soaking time with a water content of 4.68 ± 0.12%, a total phenol content of 74.53 ± 0.59 mg GAE/g, a DPPH inhibitory activity of 52.70 ± 0.86%, a FRAP value of 123.94 ± 1.39 µM/g, an α glucosidase inhibitory activity 51.56 ± 0.70%, and consumer preference levels for appearance, color, flavor, taste and overall of 4.63 ± 0.74, 4.49 ± 0.75, 4.39 ± 1.07, 4.43 ± 1.03, and 4.49 ± 0.11, respectively. read more

Amir Husni, Bayu Pamungkas, Ellya Sinurat, Alim Isnansetyo

Abstract

Cancer is a disease that is considered a problem in the health sector. Cancer treatment methods still have side effects, so a safer alternative to anticancer treatment is needed. For example, fucoidan is a sulfated carbohydrate produced by brown seaweed and known to have a wide range of bioactivity, including anticancer activity. This study aimed to characterize fucoidan from the brown seaweed Sargassum hystrix and test its cytotoxic activity against the breast cancer cell line MCF-7. Fucoidan was extracted using distilled water at 85°C and characterized by determining the yield, total sugar, and total sulfate contents and analyzing its functional groups. Fucoidan was then subjected to a cytotoxic activity test on MCF-7 breast cancer cells based on an MTT method. Results demonstrated that S. hystrix fucoidan had a yield of 6.77% ± 1.47%, total sugar content of 69.35% ± 5.83%, and a sulfate content of 26.5% ± 2.73%. Functional group analysis revealed the existence of ester and sulfate in the extract, indicating the fucoidan content. Fucoidan elicited cytotoxic effects on MCF-7 breast cancer cells and had IC50 of 555.54 µg/mL. Fucoidan-exposed cancer cells shrank. They were round and had a limited spread pattern. Thus, S. hystrix fucoidan has an anticancer activity and should be further scrutinized as a potential alternative cancer therapy. read more